Cold range day, and some problems with my JHP...

1438 Views 2 Replies 2 Participants Last post by Kneedeep971, Aug 2, 2012

Discussion Starter · Feb 8, 2008

Hello all!

I finally got back out to the range for the first time since the snow flew.. Three hours of the whole range to myself at 15 degrees, yee ha! I never thought about what a pain in bum it would be to find brass in 8 inches of snow, but oh well.

The High Point of the day (haha) was running 50 rounds of my own .45 ACP LRN (230 grain .452 LRN with x.x grains of Unique 1.270" COL) through my JHP with out a single hiccup aside from a known issue with that lot (didn't set the shoulder quite deep enough, so they stick in the chamber and don't want to eject unfired). The low point came immediately afterwards... I ran 52 rounds of FMJ through it (230gr Horandy .451 FMJ-RN with x.x grains of Unique 1.270" COL) and had serious issues. It seemed to be somewhat magazine related, though not entirely. I had one magazine (#2) which FTF every single round (No BS, every one, 3 full mags). I would blame the mag entirely, except that the same mag had just run the LRNs just fine, and other mags had FTF (lower rate). All in all, it just didn't seem to like FMJs, which seems backwards.

Before anyone yells 'hand loads', this is the EXACT same problem I had last year, running Winchester White Box and Wolf. All the bad feeds went nose up, banging into the slide above.

The one thing that pops into my head is that when I chamber and then ejected rounds, they do have noticeable feed marks on the nose where they hit the ramp. I am guessing that since the lead rounds are 'slicker' and softer, they tend to just deform and slide into the chamber, while the FMJs won't.

I have not polished my ramp, but have lightly sanded off the thick layer of paint that was chipping off, thinking that might be related.

Does anyone have any suggestions? My first thought is to polish the ramp a bit, but would like some opinions first.

Thank you!

edited by rimfirehunter to remove powder charge weights from post

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rimfirehunter

· #2 · Feb 8, 2008

The nose high jams are "generally" cause by the feed lips on the magazine being a little too wide at the very front where it touches the bullet.

The .452 sized LRN's are a bit larger than the .451 sized FMJ's, not a lot of difference but since the OAL's are the same it has to be the feed lips on the mag. I think the copper jacketed factory rounds would be a littler slicker on the mag feed lips than the cast lead rounds, so this is probably why they are jumping nose high during the feeding process.

Try adjusting the very forward part of the feed lips in a bit and see if that fixes the problem with factory loads. I would measure the ID and OD of the forward feed lips on the mag before and after adjusting and see how this works.

I do not have a HP .45acp, but this has been my exp on various HP C9 mags and several other brands/caliber of mags over the years when it comes to nose high jams when the slide is cycled by hand or when shooting.

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Kneedeep971

· #3 · Aug 2, 2012

rimfirehunter said:
The nose high jams are "generally" cause by the feed lips on the magazine being a little too wide at the very front where it touches the bullet.

The .452 sized LRN's are a bit larger than the .451 sized FMJ's, not a lot of difference but since the OAL's are the same it has to be the feed lips on the mag. I think the copper jacketed factory rounds would be a littler slicker on the mag feed lips than the cast lead rounds, so this is probably why they are jumping nose high during the feeding process.

Try adjusting the very forward part of the feed lips in a bit and see if that fixes the problem with factory loads. I would measure the ID and OD of the forward feed lips on the mag before and after adjusting and see how this works.

I do not have a HP .45acp, but this has been my exp on various HP C9 mags and several other brands/caliber of mags over the years when it comes to nose high jams when the slide is cycled by hand or when shooting.

I would have to completely agree with rimfire.

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