OAL problem in CZ75B

[Don Quixote]

I recently began reloading for my CZ75B and have run into a problem with LRN bullets. I am almost certain that the problem is not the bullet per say. They are Roger Better Bullets. They fit in my 9mm case gage perfectly. They just drop right in. I spoke to Roger and he was very helpful and I believe he has diagnosed the issue correctly, however, I am still left with problem.

The gun shoots factory FMJ just fine. From my research, the CZ75B has a very short bore causing some bullets to engage the rifling when chambered. I ran this test and it shows that the bullet is engaging the rifling (this is not my bullet, I took this picture from Kings Shooters thread, but it is exactly what is happening to me, though I am noy using coated bullets)



The solutionis to seat the bullet deeper, but here is the problem. I am already at 1.1" which is the Min OAL recommended for this powder, bullet combo. What happens if I seat the bullet deepr than recommended Min OAL? FYI, I am loading very light loads.

I know the best solution is to find a bullet with a different profile, ut I have about 495 of these LRN.

Is it safe to seat deeper than recommended OAL?

[Pkspawn]

Bump the powder down, and seat it until it fights your barrel. Then work up a new load for that powder to make whatever speeds/power factor you are loading for. Check brass for signs of overpressure.

I look at the manuals as "guides". Each firearm is slightly different. even between same make/models.

Or, just don't run that bullet profile type and see if Better Bullets is has other types.

[Don Quixote]

Or, just don't run that bullet profile type and see if Better Bullets is has other types.

Thanks. I shoot steel so I don't need to make any PF. I just need to cycle the slide. My loads were a little below Min charge already.

That's part of the plan once I use up the 497 I have left...

[mp517prct]

i ran into a similar problem a few years ago, loading Berry's Copper Plated .30 Carbine Bullets, like you i was running minimal loads (just enough to cycle the bolt), and just seated the bullets deeper and deeper using trial-and-error until they were deep enough. The CZ75 is a stout gun that can handle +P ammo. Work slowly and carefully and you should be able to seat them deep enough to make them work

[Svickstc]

Seating the bullet deeper creates greater pressure...either change powders or drop the amount of grains and work up slowly as others suggested...

Its 9mm so i dont think off the top of my head the pressures are that high to begin with?

[knight0334]

If it becomes a problem you could throat ream your barrel to cut away the rifling for relief.

The only time contact with rifling is a problem is when it pushes the bullet back into the case. Freebore on the otherhand isn't a problem if the bullets match the diameter of the grooves, or are slightly larger than the groove diameter.

[Twoboxer]

I routinely use Berry's 115gr PRN set to 1.100" out of my CZ75B without issue.

Are you certain the problem isn't the bullet's diameter? The spec says they should be 0.356", same as Berry's PRN. Are they?

[Pilot321]

If the problem persists, call CZ-USA. There CS is very good, and they will lengthen the chamber, or give you a new barrel. In the meantime, use your barrel as an OAL gauge, and seat the bullet to stay off the rifling by dropping in a round to check length.

[RobW]

Its 9mm so i dont think off the top of my head the pressures are that high to begin with?

9mm is a high pressure round. I would be very very careful - at the end of the day 500 heads is worth like 50 bucks. My advice is to sell them and get something that fits your barrel.

[Svickstc]

9mm is a high pressure round. I would be very very careful - at the end of the day 500 heads is worth like 50 bucks. My advice is to sell them and get something that fits your barrel.

Should of checked my books, don't load 9mm as its not worth my time per cost

Thanks for clearing that up