Does excessive crimp lead to stuck cases?


PDA






Franco
March 28, 2010, 08:57 PM
I posted a thread re: getting cases stuck in my 460 XVR. I'm loaded within the ranges in the manuals (albeit at the higher end), the subject of my original post, but I had a thought for this new thread.

I'm crimping pretty heavy because of the 460 recoil and I'm wondering if a heavy crimp is causing more pressure and thus stuck cases even though I'm within manufacturer load ranges (e.g. 47.5g W296 w/ Hornady XTP Mag 240g). In other words, maybe it's not the charge at all but, rather, the crimp? I am hoping that's not the case because I think the big bores should be crimped hard and I do it routinely for my 45-70 and 44 mag. I read a thread on here about someone getting stuck cases in their 44 mag and that got me to thinking (a dangerous state for sure).

Thoughts appreciated as I'm sitting on several boxes of HDY bullets, cases and 8lbs of W296 and itchin to blow stuff up. Tx.

If you enjoyed reading about "Does excessive crimp lead to stuck cases?" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
Walkalong
March 28, 2010, 11:36 PM
Doubt it, but never say never. Got pics?

Grump
March 29, 2010, 01:14 AM
Only stickiness I've ever had from crimping was on chambering, not extracting.

More bullet resistance (sealant, tight neck, crimp, and probably in that order of biggest to smallest effects) does increase chamber pressure, but really shouldn't make the difference between a safe load and an overpressure load like wide differences in case capacity can.

You may want to cross-reference your loads, or run them in QuickLOAD with all variables reliably measured. Many loads in older manuals were found to be...unwise with later and more reliable testing.

918v
March 29, 2010, 01:52 AM
If you overcrimp, you will buckle the case just behind the shoulder. When the case buckles, it grows in diameter. Bottlenecked cases are conical in profile and will wedge in the chamber under bolt pressure because the chamber is also conical in profile. This will cause a buckled case to stick.

If you stick a case, do not hammer on the bolt handle because it may break off the bolt.

Scrapperz
March 29, 2010, 02:04 AM
Try doing a full length size on your cases and then lighten up on the crimp and see what happens. Just a thought. I do not crimp as heavy as I saw in your pictures on the other thread. Hope it helps.

Link to the pictures post (http://thehighroad.org/showpost.php?p=6388285&postcount=3)

Fatelvis
March 29, 2010, 01:50 PM
If the crimp on a loaded round makes charging the cylinder more difficult, (need to force the rounds in, or pry them out), then you are using too much crimp. The crimp should not create any kind of bulge of the case.

rcmodel
March 29, 2010, 01:57 PM
I don't think a heavy crimp will add enough pressure to cause your problem. Even the heaviest crimp is going to be ironed out and the bullet on its way before max chamber pressure is reached.

I would suggest you try another brand or lot number of cases.

Yours may just be out of spec too soft.
Too soft will expand in the chamber normally but won't contract as much and let go.

rc

If you enjoyed reading about "Does excessive crimp lead to stuck cases?" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!