ERATAC T4 Block Mount Short 34 mm – Lever, 0/20 MOA

.br-v3-product{--br-green:#18392f;--br-green2:#0f2b23;--br-gold:#e8d39a;--br-cream:#f7f4ec;--br-red:#8b2c2c;--br-text:#1b1f1d;--br-muted:#59625d;--br-line:#d7ddd9;color:var(--br-text);font-family:Arial,Helvetica,sans-serif;font-size:16px;line-height:1.62;max-width:100%;overflow-wrap:anywhere}
.br-v3-product *{box-sizing:border-box}
.br-v3-product a{color:#174d3d;text-decoration:underline;text-underline-offset:2px}
.br-v3-product a:focus-visible,.br-v3-product summary:focus-visible,.br-v3-product input:focus-visible,.br-v3-product select:focus-visible{outline:3px solid #9f6c00;outline-offset:3px}
.br-v3-product p{margin:0 0 14px}
.br-v3-product ul,.br-v3-product ol{padding-left:1.3rem;margin:10px 0 18px}
.br-v3-product li{margin:.48rem 0}
.br-v3-product .br-hero,.br-v3-product .br-card,.br-v3-product .br-tip,.br-v3-product .br-compare,.br-v3-product .br-note,.br-v3-product .br-final,.br-v3-product .br-calc{padding:22px;margin:20px 0;border-radius:7px}
.br-v3-product .br-hero{background:linear-gradient(135deg,var(--br-green2),var(--br-green));color:#fff}
.br-v3-product .br-hero p,.br-v3-product .br-hero strong,.br-v3-product .br-hero li{color:#fff}
.br-v3-product .br-eyebrow{font-size:.82rem;font-weight:800;letter-spacing:.08em;text-transform:uppercase;color:var(--br-gold);margin:0 0 8px}
.br-v3-product .br-title{font-size:1.65rem;line-height:1.2;font-weight:850;margin:0 0 10px}
.br-v3-product .br-lead{font-size:1.08rem;max-width:850px}
.br-v3-product .br-section-title{font-size:1.3rem;line-height:1.25;font-weight:850;margin:32px 0 12px;color:var(--br-green)}
.br-v3-product .br-subtitle{font-size:1.08rem;line-height:1.3;font-weight:800;margin:22px 0 8px;color:var(--br-green2)}
.br-v3-product .br-card{background:var(--br-cream);border-left:5px solid var(--br-gold)}
.br-v3-product .br-tip{background:#edf4f0;border-left:5px solid var(--br-green)}
.br-v3-product .br-compare{background:#f1f2f1;border-left:5px solid #555}
.br-v3-product .br-note{background:#fff2f2;border-left:5px solid var(--br-red)}
.br-v3-product .br-final{background:var(--br-green);color:#fff}
.br-v3-product .br-final p,.br-v3-product .br-final strong,.br-v3-product .br-final li,.br-v3-product .br-final a{color:#fff}
.br-v3-product .br-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:14px;margin:16px 0 22px}
.br-v3-product .br-grid-3{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:14px;margin:16px 0 22px}
.br-v3-product .br-mini{border:1px solid var(--br-line);border-radius:7px;padding:16px;background:#fff}
.br-v3-product .br-mini p{margin:5px 0}
.br-v3-product .br-kicker{font-weight:850;color:var(--br-green);margin:0 0 6px}
.br-v3-product .br-answer{font-size:1.05rem;border:1px solid var(--br-line);border-radius:7px;padding:16px;background:#fff;margin:16px 0}
.br-v3-product .br-formula{font-weight:800;background:#fff;border:1px solid var(--br-line);border-radius:6px;padding:13px;margin:12px 0}
.br-v3-product .br-scroll{overflow-x:auto;margin:18px 0 24px;border:1px solid var(--br-line);border-radius:7px}
.br-v3-product table{width:100%;min-width:790px;border-collapse:collapse;background:#fff;font-size:.95rem}
.br-v3-product th,.br-v3-product td{padding:11px 12px;border-bottom:1px solid var(--br-line);vertical-align:top;text-align:left}
.br-v3-product th{background:#eaf0ec;color:var(--br-green2);font-weight:850}
.br-v3-product tr:last-child td{border-bottom:0}
.br-v3-product .br-calc{background:#f5f7f5;border:2px solid #becbc4}
.br-v3-product .br-calc-title{font-size:1.22rem;font-weight:850;color:var(--br-green2);margin:0 0 6px}
.br-v3-product .br-calc-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:13px;margin-top:16px}
.br-v3-product .br-field label{display:block;font-size:.9rem;font-weight:800;margin:0 0 5px;color:#25312c}
.br-v3-product .br-field input,.br-v3-product .br-field select{width:100%;min-height:44px;border:1px solid #aebbb4;border-radius:5px;padding:9px 10px;background:#fff;color:#18201c;font:inher
.it}
.br-v3-product .br-help{font-size:.83rem;color:var(--br-muted);margin:5px 0 0}
.br-v3-product .br-result{border:1px solid #9eaea5;background:#fff;border-radius:7px;padding:17px;margin-top:18px}
.br-v3-product .br-result-title{font-size:1.12rem;font-weight:850;color:var(--br-green2);margin-bottom:8px}
.br-v3-product .br-result-ok{border-left:5px solid #1d6d49}
.br-v3-product .br-result-warn{border-left:5px solid var(--br-red)}
.br-v3-product .br-result a{display:inline-block;font-weight:850;margin-top:8px}
.br-v3-product .br-badge{display:inline-block;border-radius:99px;padding:4px 9px;background:#e8eee9;color:#24322b;font-size:.82rem;font-weight:800;margin:2px 4px 2px 0}
.br-v3-product details{background:#f2f3f2;color:#1b1f1d;padding:12px 14px;margin:10px 0;border-radius:6px}
.br-v3-product summary{cursor:pointer;font-weight:800;color:#153d32}
.br-v3-product details p{margin:10px 0 2px}
.br-v3-product .br-steps{counter-reset:brstep;list-style:none;padding:0;margin:16px 0}
.br-v3-product .br-steps li{counter-increment:brstep;position:relative;padding:2px 0 14px 46px;min-height:38px}
.br-v3-product .br-steps li:before{content:counter(brstep);position:absolute;left:0;top:0;width:32px;height:32px;border-radius:50%;display:flex;align-items:center;justify-content:center;background:var(--br-green);color:#fff;font-weight:850}
@media (max-width:850px){.br-v3-product .br-calc-grid,.br-v3-product .br-grid-3{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media (max-width:720px){.br-v3-product{font-size:16px;line-height:1.55}.br-v3-product .br-hero,.br-v3-product .br-card,.br-v3-product .br-tip,.br-v3-product .br-compare,.br-v3-product .br-note,.br-v3-product .br-final,.br-v3-product .br-calc{padding:17px;margin:16px 0}.br-v3-product .br-title{font-size:1.36rem}.br-v3-product .br-section-title{font-size:1.17rem}.br-v3-product .br-grid,.br-v3-product .br-grid-3,.br-v3-product .br-calc-grid{grid-template-columns:1fr}.br-v3-product th,.br-v3-product td{padding:9px}}



ERATAC T4 short · 34 mm main tube · Safety lever · 0 and 20 MOA
Classic ERATAC block mount – calculated with height, objective, and cant
This page exclusively covers the short ERATAC T4 for 34 mm main tubes. 10 real manufacturer SKUs cover 0 and 20 MOA and axis heights from 30 to 50 mm. The calculator checks the measured objective outer dimension and links the matching T4/T5 version.


Direct answer: T4 is the right clamp for frequent mounting and dismounting. The main tube must measure exactly 34 mm. The lowest suitable variant results from objective outer ÷ 2 + highest contour + desired clearance + accessory thickness + drop due to 20 MOA.
The classic ERATAC generation differs from T7 by its 25 mm wide rings with UNIVERSAL interface. This allows the proven T4/T5 mounts to be used. T7 accessories do not fit. The short design is intended by the manufacturer for bolt-action rifles and AR10-type weapons; in the end, the real rail position and your eye relief decide.

Four points to clarify before purchase


1. T4 or T5?
T4: The clamping force can be adjusted to the Picatinny rail; a safety prevents unintentional opening.


2. Main tube
Only for 34 mm. Other diameters require their own ring geometry. A 30 mm version must not be used for 34 or 36 mm.


3. Height
BH is the distance below the tube. For collision calculation, the axis height counts. This page covers 30 to 50 mm.


4. 0 or 20 MOA?
0 MOA remains neutral; 20 MOA provides reserve for distance setups. At the front objective, the cant reduces the free height.

ERATAC Classic Finder: T4/T5, diameter and height

Enter setup
The finder checks all 42 short classic T4/T5 SKUs from the current price list. It deliberately shows "no variant" if the chosen combination is not produced.


Clamping T4 safety lever
T5 hex nuts
Choose by frequency of change.


Main tube 30 mm
34 mm
36 mm Must fit the scope exactly.


Objective outer Largest actual outer dimension.


Highest contour relative to the rail 0 = rail top edge, −5 = 5 mm lower.


Desired clearance 2 mm
3 mm
4 mm
5 mm Reserve to the highest contour.


Cover/adapter per side 0 mm
1 mm
2 mm
3 mm
4 mm
5 mm Only add if not measured together.


Forward tilt 0 MOA
20 MOA 20 MOA = about 5.82 mrad.


Ring center to collision point 50 mm
75 mm
100 mm
125 mm
150 mm
175 mm
200 mm For the 20-MOA drop.


Scope overall length 250 mm
275 mm
300 mm
325 mm
350 mm
375 mm
400 mm
425 mm
450 mm Warning value for position and collision.


The calculator is loading.

Calculator limit: It checks the vertical collision height. Lateral barrel contour, bolt, adjustment ring, eyepiece, bolt handle, clip-on adapter and your head position must also fit the actual setup.

All 10 variants of this page


Forward tilt / BH
Axis height
Weight
Objective outer at 3 mm clearance
Classification



0 MOA / BH 13 mm
30 mm
268 g
up to 54 mm
lowest line; still check outer dimension and stop.


0 MOA / BH 17.5 mm
34.5 mm
283 g
up to 63 mm
medium gradation; still check outer dimension and stop.


0 MOA / BH 21.5 mm
38.5 mm
317 g
up to 71 mm
medium gradation; still check outer dimension and stop.


0 MOA / BH 25 mm
42 mm
333 g
up to 78 mm
medium gradation; still check outer dimension and stop.


0 MOA / BH 31 mm
48 mm
374 g
up to 90 mm
medium gradation; still check outer dimension and stop.


20 MOA / BH 13 mm
approx. 30 mm
269 g
up to approx. 52.8364 mm
lowest line; still check outer dimension and stop.


20 MOA / BH 19.5 mm
approx. 36.5 mm
293 g
up to approx. 65.8364 mm
medium gradation; still check outer dimension and stop.


20 MOA / BH 23 mm
approx. 40 mm
327 g
up to approx. 72.8364 mm
medium gradation; still check outer dimension and stop.


20 MOA / BH 27 mm
approx. 44 mm
348 g
up to approx. 80.8364 mm
medium gradation; still check outer dimension and stop.


20 MOA / BH 33 mm
approx. 50 mm
381 g
up to approx. 92.8364 mm
largest height reserve; still check outer dimension and stop.



At 20 MOA, a 100 mm distance from the front ring center to the collision point is included in the objective limit. For your scope, use the finder with the actual distance.

Four typical setups


Compact objective
46 mm outer, 3 mm clearance, 0 MOA: requires 26 mm AH. The low available line fits mathematically.


Large housing
92 mm outer, 3 mm clearance, 0 MOA: requires 49 mm AH. The highest available line is intended for this.


20 MOA / 150 mm
The tilt lowers the collision point by about 0.87 mm. This reserve must be present in addition to the objective half, contour and desired clearance.


Objective cover retrofitted
If the radius grows by 2 mm due to cover or adapter, the required axis height also increases by 2 mm. Do not calculate with the lens diameter.

T4 vs T5: same geometry, different workflow

T4 safety lever: for frequent removal, adjustable clamping force, secured levers and operation even with gloves.
T5 hex nuts: for permanently screwed setups, self-locking special thread and less weight than the corresponding lever variant.
The choice does not change the tube diameter or height calculation. It changes how often and with what tool you want to loosen the mount. The price of this page is €424.90; the RRP remains as a comparison price.

Mounting procedure for reproducible results


Secure and unload the firearm. Check rail, clamping surfaces and screws for firm fit and damage.

Position only hand-tight. First eye distance and usable clamping section in the r
ealize the correct cheek weld.

Insert barrel straight. Do not clamp transitions, turrets, or tapering into the rings.

Check objective clearance. Consider caps, adapters, barrel contour, and 20-MOA drop.

Align reticle. An ERATAC ZFIX alignment aid can help ensure parallel starting position.

Tighten according to manufacturer specifications. Work evenly and with a suitable torque tool.

Check zero point. Any change to the optic system requires point of impact verification.

Trainer tip: The lowest collision-free mount is not automatically ergonomically correct. Check three positions according to the calculation: prone, kneeling, and standing. If you have to press your head noticeably downward in one position, the cheek rest or mounting height is not yet properly adjusted.

Suitable accessories for the classic UNIVERSAL interface



Additional Picatinny surface: ERATAC Picatinny adapter .

Red dot/interface solutions: ERATAC mounting plates and interface adapters .

Reduce 30 mm to 1 inch: ERATAC reducing rings ; choose the appropriate T4/T5 version.

Alignment: ERATAC ZFIX .

Deeper height selection: Guide to ERATAC mounting height .

Do not confuse: This T4/T5 side uses the classic UNIVERSAL interface. T7 adapters do not belong on this mount.

Technical practical data


Feature
Value
Purchase relevance


Series
T4 GEN-2
Safety lever; select according to frequency of change.


Main tube
34 mm
Exclusively for exactly 34 mm.


Design
short
120 mm total length / 70 mm base length; check rail surface and eye relief.


Rings
25 mm wide
Clamping section of the scope must be straight and free on both rings.


Forward tilt
0 and 20 MOA
20 MOA reduces objective clearance forward.


Axis heights
30 / 34.5 / 36.5 / 38.5 / 40 / 42 / 44 / 48 / 50 mm
Crucial value for collision calculation.


Weight
268–381 g
Depending on BH and forward tilt; specific values are in the matrix.


Material/finish
7075 aluminum, hard anodized type III, matte black
Manufacturer specification for the classic ERATAC series.


Interface
UNIVERSAL T4/T5
Classic accessory; not compatible with T7 adapters.

Scope of delivery
1 × ERATAC T4 short block mount for 34 mm main tube in the chosen height and forward tilt
Scope, Picatinny rail, torque tool, reducing rings, ZFIX and adapters are not included unless separately specified.

Frequently asked questions
What is the difference between T4 and T5? T4 uses secured quick-release levers with adjustable clamping force. T5 is screwed with self-locking hex nuts. Height, tube diameter, and forward tilt remain independent selection points.
Does this mount fit Weaver? The product family is designed for Picatinny. A blanket approval for differing Weaver geometries would be unreliable; rail dimensions and manufacturer approval must match.
Why is “56 mm objective” not enough? Because 56 mm usually refers to the free lens diameter. For mounting, the largest outer diameter of the housing including cap or adapter counts.
How much height does 20 MOA cost? The additional drop depends on the distance. About 0.58 mm at 100 mm and 0.87 mm at 150 mm from the front ring center to the collision point.
Can I use T7 accessories? No. T4 and T5 use the classic UNIVERSAL interface. T7 has its own, incompatible accessory system.
Can I use 30 mm with reducing rings to 1 inch? Only with ERATAC reducing rings expressly designed for T4/T5 and only if the scope and clamping section are suitable.
Which variant is right for a large objective? This can only be determined with the actual outer diameter, the highest contour, and the desired clearance. The finder selects the lowest mathematically suitable series height.
Is the short design always r
Important for repeaters? No. It is designed for that, but eye relief, rail length, and usable clamping section must fit the specific setup. If an offset is necessary, an extended mount is more sensible.
Black-Raptor recommendation: Choose T4 if frequent mounting and dismounting is your actual workflow. Then confirm the barrel diameter exactly and calculate the height with the outer dimension. Do not order based on scope name or lowest BH.

(function(){
var root=document.getElementById('br-classic-finder');if(!root){return;}
var mounts=[{series:'T4',tube:30,moa:0,bh:10,ah:25,weight:240,sku:'T4013-0010',url:'/products/eratac-t4-blockmontage-kurz-30-mm?variant=59242033545564'},
{series:'T4',tube:30,moa:0,bh:15,ah:30,weight:264,sku:'T4013-0015',url:'/products/eratac-t4-blockmontage-kurz-30-mm?variant=59242033578332'},
{series:'T4',tube:30,moa:0,bh:20,ah:35,weight:294,sku:'T4013-0020',url:'/products/eratac-t4-blockmontage-kurz-30-mm?variant=59242033611100'},
{series:'T4',tube:30,moa:0,bh:23,ah:38,weight:318,sku:'T4013-0023',url:'/products/eratac-t4-blockmontage-kurz-30-mm?variant=59242033643868'},
{series:'T4',tube:30,moa:0,bh:33,ah:48,weight:375,sku:'T4013-0033',url:'/products/eratac-t4-blockmontage-kurz-30-mm?variant=59242033676636'},
{series:'T4',tube:30,moa:20,bh:15,ah:30,weight:264,sku:'T4013-2015',url:'/products/eratac-t4-blockmontage-kurz-30-mm?variant=59242033709404'},
{series:'T4',tube:30,moa:20,bh:22,ah:37,weight:310,sku:'T4013-2022',url:'/products/eratac-t4-blockmontage-kurz-30-mm?variant=59242033742172'},
{series:'T4',tube:30,moa:20,bh:25,ah:40,weight:333,sku:'T4013-2025',url:'/products/eratac-t4-blockmontage-kurz-30-mm?variant=59242033774940'},
{series:'T4',tube:30,moa:20,bh:35,ah:50,weight:384,sku:'T4013-2035',url:'/products/eratac-t4-blockmontage-kurz-30-mm?variant=59242033807708'},
{series:'T4',tube:34,moa:0,bh:13,ah:30,weight:268,sku:'T4014-0013',url:'/products/eratac-t4-blockmontage-kurz-34-mm?variant=59242033840476'},
{series:'T4',tube:34,moa:0,bh:17.5,ah:34.5,weight:283,sku:'T4014-0017',url:'/products/eratac-t4-blockmontage-kurz-34-mm?variant=59242033873244'},
{series:'T4',tube:34,moa:0,bh:21.5,ah:38.5,weight:317,sku:'T4014-0021',url:'/products/eratac-t4-blockmontage-kurz-34-mm?variant=59242033906012'},
{series:'T4',tube:34,moa:0,bh:25,ah:42,weight:333,sku:'T4014-0025',url:'/products/eratac-t4-blockmontage-kurz-34-mm?variant=59242033938780'},
{series:'T4',tube:34,moa:0,bh:31,ah:48,weight:374,sku:'T4014-0031',url:'/products/eratac-t4-blockmontage-kurz-34-mm?variant=59242033971548'},
{series:'T4',tube:34,moa:20,bh:13,ah:30,weight:269,sku:'T4014-2013',url:'/products/eratac-t4-blockmontage-kurz-34-mm?variant=59242034004316'},
{series:'T4',tube:34,moa:20,bh:19.5,ah:36.5,weight:293,sku:'T4014-2019',url:'/products/eratac-t4-blockmontage-kurz-34-mm?variant=59242034037084'},
{series:'T4',tube:34,moa:20,bh:23,ah:40,weight:327,sku:'T4014-2023',url:'/products/eratac-t4-blockmontage-kurz-34-mm?variant=59242034069852'},
{series:'T4',tube:34,moa:20,bh:27,ah:44,weight:348,sku:'T4014-2027',url:'/products/eratac-t4-blockmontage-kurz-34-mm?variant=59242034102620'},
{series:'T4',tube:34,moa:20,bh:33,ah:50,weight:381,sku:'T4014-2033',url:'/products/eratac-t4-blockmontage-kurz-34-mm?variant=59242034135388'},
{series:'T4',tube:36,moa:20,bh:21.5,ah:39.5,weight:301,sku:'T4016-2021',url:'/products/eratac-t4-blockmontage-kurz-36-mm?variant=59242034463068'},
{series:'T4',tube:36,moa:20,bh:31.5,ah:49.5,weight:377,sku:'T4016-2031',url:'/products/eratac-t4-blockmontage-kurz-36-mm?variant=59242034495836'},
{series:'T5',tube:30,moa:0,bh:10,ah:25,weight:221,sku:'T5013-0010',url:'/products/eratac-t5-blockmontage-kurz-30-mm?variant=59242035380572'},
{series:'T5',tube:30,moa:0,bh:15,ah:30,weight:244,sku:'T5013-0015',url:'/products/eratac-t5-blockmontage-kurz-30-mm?variant=59242035413340'},
{series:'T5',tube:30,moa:0,bh:20,ah:35,weight:274,sku:'T5013-0020',url
:'/products/eratac-t5-blockmount-kurz-30-mm?variant=59242035446108'},
{series:'T5',tube:30,moa:0,bh:23,ah:38,weight:298,sku:'T5013-0023',url:'/products/eratac-t5-blockmount-kurz-30-mm?variant=59242035478876'},
{series:'T5',tube:30,moa:0,bh:33,ah:48,weight:355,sku:'T5013-0033',url:'/products/eratac-t5-blockmount-kurz-30-mm?variant=59242035511644'},
{series:'T5',tube:30,moa:20,bh:15,ah:30,weight:244,sku:'T5013-2015',url:'/products/eratac-t5-blockmount-kurz-30-mm?variant=59242035544412'},
{series:'T5',tube:30,moa:20,bh:22,ah:37,weight:290,sku:'T5013-2022',url:'/products/eratac-t5-blockmount-kurz-30-mm?variant=59242035577180'},
{series:'T5',tube:30,moa:20,bh:25,ah:40,weight:314,sku:'T5013-2025',url:'/products/eratac-t5-blockmount-kurz-30-mm?variant=59242035609948'},
{series:'T5',tube:30,moa:20,bh:35,ah:50,weight:364,sku:'T5013-2035',url:'/products/eratac-t5-blockmount-kurz-30-mm?variant=59242035642716'},
{series:'T5',tube:34,moa:0,bh:13,ah:30,weight:240,sku:'T5014-0013',url:'/products/eratac-t5-blockmount-kurz-34-mm?variant=59242035675484'},
{series:'T5',tube:34,moa:0,bh:17.5,ah:34.5,weight:264,sku:'T5014-0017',url:'/products/eratac-t5-blockmount-kurz-34-mm?variant=59242035708252'},
{series:'T5',tube:34,moa:0,bh:21.5,ah:38.5,weight:298,sku:'T5014-0021',url:'/products/eratac-t5-blockmount-kurz-34-mm?variant=59242035741020'},
{series:'T5',tube:34,moa:0,bh:25,ah:42,weight:314,sku:'T5014-0025',url:'/products/eratac-t5-blockmount-kurz-34-mm?variant=59242035773788'},
{series:'T5',tube:34,moa:0,bh:31,ah:48,weight:355,sku:'T5014-0031',url:'/products/eratac-t5-blockmount-kurz-34-mm?variant=59242035806556'},
{series:'T5',tube:34,moa:20,bh:13,ah:30,weight:240,sku:'T5014-2013',url:'/products/eratac-t5-blockmount-kurz-34-mm?variant=59242035839324'},
{series:'T5',tube:34,moa:20,bh:19.5,ah:36.5,weight:273,sku:'T5014-2019',url:'/products/eratac-t5-blockmount-kurz-34-mm?variant=59242035872092'},
{series:'T5',tube:34,moa:20,bh:23,ah:40,weight:308,sku:'T5014-2023',url:'/products/eratac-t5-blockmount-kurz-34-mm?variant=59242035904860'},
{series:'T5',tube:34,moa:20,bh:27,ah:44,weight:329,sku:'T5014-2027',url:'/products/eratac-t5-blockmount-kurz-34-mm?variant=59242035937628'},
{series:'T5',tube:34,moa:20,bh:33,ah:50,weight:362,sku:'T5014-2033',url:'/products/eratac-t5-blockmount-kurz-34-mm?variant=59242035970396'},
{series:'T5',tube:36,moa:20,bh:21.5,ah:39.5,weight:282,sku:'T5016-2021',url:'/products/eratac-t5-blockmount-kurz-36-mm?variant=59242036035932'},
{series:'T5',tube:36,moa:20,bh:31.5,ah:49.5,weight:357,sku:'T5016-2031',url:'/products/eratac-t5-blockmount-kurz-36-mm?variant=59242036068700'}];
function num(id){return parseFloat(document.getElementById(id).value)||0;}
function fmt(n){return (Math.round(n*10)/10).toLocaleString('de-DE',{minimumFractionDigits:1,maximumFractionDigits:1});}
function esc(s){return String(s).replace(/[& "]/g,function(c){return {'&':'&',' ':'>','"':'"'}[c];});}
function calc(){
var series=document.getElementById('brCSeries').value,tube=num('brCTube'),obj=num('brCObj'),obstacle=num('brCObstacle'),clear=num('brCClear'),extra=num('brCExtra'),moa=num('brCMoa'),front=num('brCFront'),length=num('brCLength');
var drop=Math.tan((moa/60)*Math.PI/180)*front,need=obj/2+obstacle+clear+extra+drop;
var candidates=mounts.filter(function(m){return m.series===series&&m.tube===tube&&m.moa===moa;}).sort(function(a,b){return a.ah-b.ah;}),match=null;
for(var i=0;i =need){match=candidates[i];break;}}
var result=document.getElementById('brCResult'),lengthNote=length>=400?'Long scope: Check eyepiece, adjustment ring and rail end additionally.':'Total length is only a position hint; the real eye relief decides.';
if(match){var actual=match.ah-obj/2-obstacle-extra-drop;result.className='br-result br-result-ok';result.innerHTML=' Fits: '+match.series+' · '+match.tube+' mm · '+match.moa+' MOA · BH '+String(match.bh).re
place('.',',')+' mm AH '+fmt(match.ah)+' mm '+match.weight+' g Required axle height: '+fmt(need)+' mm . Calculated free clearance: '+fmt(actual)+' mm . 20-MOA portion at '+front+' mm: '+fmt(drop)+' mm. '+lengthNote+' Open matching ERATAC variant ';}
else{result.className='br-result br-result-warn';result.innerHTML=' No standard variant for this combination Required axle height: '+fmt(need)+' mm . Check inputs, different clamp or another design. A non-produced combination will not be suggested. ';}
}
['brCSeries','brCTube','brCObj','brCObstacle','brCClear','brCExtra','brCMoa','brCFront','brCLength'].forEach(function(id){var el=document.getElementById(id);el.addEventListener('input',calc);el.addEventListener('change',calc);});calc();
})();