When you are changing your feeding system to a different caliber, experiencing feeding issues, or you have a specific caliber you are starting to use such as a wildcat cartridge – adjusting the feed lips may be necessary. This simple tutorial will walk you through how to flawlessly feed the caliber you’re wanting to use quickly without having to purchase a new magazine box.
What you’ll need:
- DBM Conversion Kit (comes with floorplate and magazine – direct drop-in replacement for a standard Remington 700 BDL; no inletting required)
- Feed lip adjustment tool
- Calipers
When is adjusting the feed lips on your detachable magazine feeding system necessary?
- Changing to a different caliber
- You have a caliber that is not listed on our website such as wildcat cartridges
- You’re experiencing feeding issues
The H-S Precision adjustment tool is constructed of aluminum which prevents scratches to the magazine finish. The milled slot with a beveled edge slips over the feed lips so you can confidently adjust the front and rear widths to the caliber-specific dimensions (below).
Simply slide the tool with the beveled side towards the inside of the magazine over the rail. Then, apply slight amounts of pressure inwards to tighten the gap and outwards to widen. Be sure to adjust both sides equally to keep the original center feed design.
The adjustment tool does come with an attached ruler guide. However, for best results, we suggest using a pair of calipers. Measure the rear gap and then the front gap (as close as possible to the ends of the magazine box) to take current measurements of your feeding system.
Next, you will want to find the caliber listed on your instruction sheet (or below) to find the correct adjustment measurements needed. Determine the amount needed to open or close the feeding system gap and use your adjustment tool accordingly to bend into place; then, measure the changes with calipers. Repeat these steps until your gap dimensions are correct according to the specification guide.
Once your dimensions have been reached, load the cartridges outside of your rifle to ensure uniformity and proper feeding.
If you have any more questions on adjusting the feed lips on your detachable magazine feeding system, contact us here or give us a call at 605-341-3006.
Setting Feed Gap
- Place the adjustment tool over the rail with the beveled side towards the inside of the magazine. Fig. 1
- Angle bender along rail diagonally as shown to widen or reduce front gap. Bend both rails the same amount. Fig. 2
- Angle bender along rail diagonally as shown to widen or reduce rear gap. Bend both rails the same amount. Fig. 3
- Check straightness by placing the straight edge of the bending tool against each rail. Fig 4.
- Check front and rear gaps with a Vernier caliper for best results. The scale on the bending tool can be used but will only give approximate results.
Feed Gap Specifications
NOTE: Feed Gap specifications below are a close starting point. Small adjustments may be necessary for best performance. If large adjustments have been made and it’s still feeding improperly, check the clearance between the bolt and the top of the magazine feed rails. There should be roughly 1/32” to 1/16” clearance while pushing UP on the magazine. Excessive clearance will cause feeding malfunction.
| Short Action Cartridge | Magazine # | Magazine # | Magazine # | Front Gap | Rear Gap |
| Low Cap | Med Cap | High Cap | |||
| Remington: 17, 222, 223 204 Ruger | 7369 | 7527 | .325 | .312 | |
| 350 Legend | 7369 | 5727 | .325 | .312 | |
| 6.5 Grendel, 6mm ARC | 7369 | 7527 | .360 | .370 | |
| 22 Nosler | 7556 | 7554 | .360 | .370 | |
| 224 Valkyrie | 7556 | 7554 | .360 | .370 | |
| 300 AAC Blackout | 7369 | .325 | .312 | ||
| 22-250 Rem | 7368 | .380 | .380 | ||
| 220 Swift | 7371 | See Fig. 5 | See Fig. 5 | ||
| 6mm Rem 257 Roberts | 7372 | 7384 | .400 | .420 | |
| 284 Win | 7373 | 7375 | 7393 | .435 | .425 |
| Short Action Ultra Mag SAUM: 6.5mm, 7mm, 300 | 7372 | 7375 | 7376 | .485 | .490 |
| Winchester Short Mag WSM: 7mm, 270, 300, 325 | 7372 | 7375 | 7376 | .485 | .490 |
| Ruger Compact Mag RCM: 300, 338 | 7372 | 7384 | 7393 | .450 | .480 |
| 35 Rem | 7372 | .395 | .410 | ||
| Remington Magnum: 6.5mm, 350 | 7372 | 7384 | 7393 | .460 | .445 |
| Creedmoor: 6mm, 6.5mm, 22 Remington: 7mm-08, 260 Winchester: 243, 308, 358 338 Federal 6 GT 6.5 Lapua 6 XC | 7372 | 7384 | 7376 | .410 | .420 |
| Long Action Cartridge | Magazine # | Magazine # | Front Gap | Rear Gap |
| Low Cap | High Cap | |||
| 7×57 Mauser, 6.5×55, 6.5×55 Swedish | 7377 (< 3.061 COAL) | .415 | .425 | |
| 7381 (> 3.061 COAL) | .395 | .410 | ||
| 6.5 PRC | 7390 (< 3.061 COAL) | .450 | .480 | |
| 7379 (> 3.061 COAL) | .440 | .450 | ||
| 240 Wby Mag | 7377 | .395 | .410 | |
| 6.5×284 Norma | 7390 (< 3.061 COAL) | .450 | .430 | |
| 7380 (> 3.061 COAL) | .440 | .450 | ||
| (> 3.061 COAL) 7367 | .395 | .410 | ||
| 300 H&H Mag | 7380 | .420 | .460 | |
| 300 Win Mag | 7379 | 7382 | .440 | .450 |
| 7mm STW 8mm Rem Mag | 7379 | 7367 | .440 | .450 |
| 338 Lapua | 7381 | 7382 | .475 | .440 |
| Norma Magnum: 300, 338 | 7381 | 7396 | .475 | .440 |
| Remington Magnum: 7mm Winchester Magnum: 264, 338 Norma Magnum: 308, 358 | 7379 | 7367 | .440 | .450 |
| Weatherby Magnum: 7mm, 257, 270, 300, 340 | 7379 | 7367 | .440 | .450 |
| Remington: 25-06, 280, 280 Ackley Improved 30-06 Springfield 35 Whelen 270 Winchester | 7381 | 7396 | .395 | .410 |
| Nolser: 26, 27, 28, 30, 33 | 7379 | 7367 | .460 | .460 |
| 375 H&H Mag | 7379 | .420 | .460 | |
| 7396 | .395 | .410 | ||
| 7mm LRM, 300 PRC , 375 Ruger | 7381 | 7396 | .440 | .450 |
| Remington Ultra Magnum RUM: 7mm, 338, 300, 375 | 7379 | 7367 | .460 | .460 |
| Weatherby magnum: 30-378, 378 | 7381 | .490 | .490 | |
| 416 Rigby | 7381 | .490 | .500 | |
| 416 Rem Mag, 458 Lott | 7379 | .440 | .450 | |
| 458 Win Mag | 7379 | 7367 | .440 | .450 |
