Bullet Creep!

[mad_matt]

Hi everyone. I've been reading here for a while and soaking up a lot of great info. Got a question for ya.
I have an 18" GLFA upper on my Aero precision AR15 carbine lower.
I'm reloading Hornady 250g FTX bullets into once fired hornady brass, Lil Gun and H110 powder, CCI450 primers and crimping to 0.473" with a Lee Factory Crimp Die(not the seating die). The problem is that my bullets are moving forward in the cases when they load into the chamber from the magazine. (ie. when the bolt slams them home) I loaded my last batch at 2.235"OAL with crimp. If I cycle them through the action they come out around 2.252"OAL

2 Questions:
1: When sizing, I am bumping the case neck tighter from 0.480" onece fired to .475" sized. Should I re-size smaller/tighter to get better neck tension? Would this keep the bullet in place better, or just over work my brass? The bullet is not loose in the case when loaded.

2: Will a modified 460 FCD side crimp fix this? From what I've read they have been useful for keeping the bullet from pushing INTO the case. Is it effective to keep the bullet from jumping OUT of the case also?

If this has been coverd I apoligize. Please send me in the right direction. I am hesitant to go buy more dies and cut them without making sure that's what I need. Thanks, Matt.

[Hoot]

Welcome Aboard Matt!

That's what I hate about smooth sided bullets. They're hard for a taper crimp or FCD to find something to hang onto. I much prefer cannelured bullets or ones with driving bands and grooves to force the mouth crimp down into. Any bullet crimping system that resists setback will likewise, resist pulling from slam chambering.

A modified Lee FCD that imparts a side crimp will help anchor the smooth sided bullets in place, though it may take some experimentation to determine the least amount of side crimp needed to get the job done. The least amount necessary is the best practice, lest you distort the bullet into an hourglass shape. Even that is not a deal breaker but my personal experience has been that side crimped bullets don't group quite as tight as mouth crimped ones. Again when you're just concerned with Minute of Deer precision, at moderate distances, it won't much matter.

Hoot

[Bmt85]

What is your inner case mouth opening after sizing? The tighter the case mouth, the better the hold, to a point. You also have to worry about trying to seat flat based bullets when trying to go tighter on sizing. You don't want to use an expander die, because that usually hurts your neck tension. I would also recommend using a VLD inside chamfer tool. I've found I don't crush cases when using it instead of a regular inside chamfer tool. Also, I personally wouldn't recommend stab crimping a sooth sided bullet

But like Hoot pointed out, smooth sided bullets have a greater chance of moving around. You could always try rolling your own cannelure. That can be quite expensive though.

[mad_matt]

Thanks for the replies!
Bmt85, good question. I just checked a handfull of sized cases with my digital caliper and the inside of the case mouths are about 0.449-.450". I have not been using an expander(since I read it on here ) I have been using a standard RCBS chamfer tool but have had no problems seating bullets yet. Would you recommend more crimp? Thanks.

Hoot, Thanks for the reply. The gun is primarily for deer season but I can't help shooting for good groups too. With a red dot I am getting around 1" groups at 100yds on my good targets and I'm thrilled with that. So far that's with factory ammo. My hand loads with Lil Gun and H110 are about 1.25" on a good group. I'd love to get a deer with my hand loaded rounds! I have been using the 250 FTX's because I felt sure they would work well in my 18" 1:24 twist barrel. Do you recommend a bullet with a cannelure in that range that holds up well to deer? I have been thinking about the barnes 275gr xbp (.451dia) but am concerned about a heavier bullet with the 1:24 twist and the smaller diameter since I'm already having 'crimp trouble'. I have also seen more new bullets out in the last year. I'd love to hear your opinion on bullet options. Also, would a cannelure bullet with Lee FCD negate the need for a side crimp in your expierence?

Thanks again for the help, guys! I appreciate it. Matt

[Al in Mi]

If your using a Lee die set, they had a bad run of sizer dies awhile back that weren't sizing the cases for enough tension.

[Hoot]

T...snip...
Hoot, Thanks for the reply. The gun is primarily for deer season but I can't help shooting for good groups too. ...snip... Do you recommend a bullet with a cannelure in that range that holds up well to deer? I have been thinking about the barnes 275gr xbp (.451dia) but am concerned about a heavier bullet with the 1:24 twist and the smaller diameter since I'm already having 'crimp trouble'. I have also seen more new bullets out in the last year. I'd love to hear your opinion on bullet options. Also, would a cannelure bullet with Lee FCD negate the need for a side crimp in your expierence?

Thanks again for the help, guys! I appreciate it. Matt

A 1:24 twist will stabilize the Barnes 275 just fine. Where I hunt in the northwoods, a 100 yd shot is almost out of the question, with most being 50 yds or less. For that reason, I'm a big fan of the Barnes 200gr XPB. Over Lil Gun, it will deliver a TKO value equal to or beyond a 30-06 shooting a 200gr bullet. What's not to love? For CXP2 game like deer, that's plenty of oomph. The grooves on that bullet provide a sharp cliff to crimp down into enough that the bullet wont go anywhere and being just 200 gr, it has less pulling inertia than heavier bullets.

Love them 200 XPB's!



Hoot

[mad_matt]

Thanks Hoot. I was looking at the 200gr xpb on some of your posts. Do the grooves on the 275 match the 200? Would they crimp the same depending on OAL? If so, I'll focus on changing bullets over adding more crimps to flat sided FTX's. My shots are up to about 125yds here in Ohio.

One last question; do the specs on my sized cases look correct? Should I be concerned about my lee sizing die? Thanks again!

[Hoot]

Thanks Hoot. I was looking at the 200gr xpb on some of your posts. Do the grooves on the 275 match the 200? Would they crimp the same depending on OAL? If so, I'll focus on changing bullets over adding more crimps to flat sided FTX's. My shots are up to about 125yds here in Ohio.

One last question; do the specs on my sized cases look correct? Should I be concerned about my lee sizing die? Thanks again!

I can't speak to the Lee sizing die as I got the Hornady set. I like Hornady's seating dies, with their bullet aligner, a lot. The grooves are the same spec, just more of them on the 275 XPB since it has a longer body. I am told that the 275 TSX is a little different in that regard.

As many years as I've been reloading for the 450b, somewhere north of 2500 rounds, I'm embarrassed to say that I've never measure the diameter of a resized case prior to crimping it as I never had an issue with the Hornady resizing die. A long while back, I did do some experimenting with sizing the case with a 45 LC die, down as far as the bullet seated to impart a little more native neck tension. I believe I jokingly referred to it as the "TNT" project. (Tight Neck Tension) It did not tighten up groups however so the concept went the way of other good ideas that did not come to fruition.

Hoot

[Bmt85]

Thanks for the replies!
Bmt85, good question. I just checked a handfull of sized cases with my digital caliper and the inside of the case mouths are about 0.449-.450". I have not been using an expander(since I read it on here ) I have been using a standard RCBS chamfer tool but have had no problems seating bullets yet. Would you recommend more crimp? Thanks.

I would say it depends. If you are running .452 bullets, then you should good. If .451, maybe. If you plan on running the Barnes 275 TSX, then yes. That bullet actually has a diameter around .450-.4505.

To your question about the 200 XPB and the 275 TSX. The driving bands are the same distance apart. I load the 200 XPB and the 275 TSX to the first driving band, and I am able to stab crimp the same for both bullets. The 275 TSX load ends up around 2.34ish", so a windowed mag is required. The 275 XPB should be the same, just an additional band by the ogive. I don't know what the actual diameter of the XPB's are, though. That could affect your loads a little, but shouldn't be much.

The 200 XPB is a nice bullet. For the range you stated, it would be a good choice. Only thing I would watch for is your velocity. The 200 XPB has a minimum velocity around 1800fps, or maybe 1700fps. I would just figure 1800fps. It also has a poor ballistic coefficient, so you need a decent amount of velocity to get any expansion at 125yds. It shouldn't be a problem to get that speed, you might just have to lean on it a little.

[Hoot]

In my AR platform, I stopped at 2500 fps for the 200 XPB. There is an XPB meta thread located Here, linking the work I did with them, including water shots where I simulated the velocity at different distances and correlated them to expansion. At 125 yds, it still expands admirably!

Hoot