Jump to content
Brian Enos's Forums... Maku mozo!

Case dimension changes from resizing to bullet seating


Jkp1987

Recommended Posts

Question for this knowledgeable forum... I am loading once fired 9mm brass on a Dillon 650XL (titegroup and berry 115g RN). When I resize and deprime the cases they fit my EGW 9mm 50 hole chamber checker easily. After I run the brass all the way through and have finished ammunition, more than half of them do not fit properly in the same chamber checker. Interestingly, the same rounds fit fine in a Dillon single case gauge. I am having the same issue with 308 I am loading on RCBS Rock Chucker. 
 

Any thoughts what I might have set up incorrectly? I appreciate the input!

 

jkp

Link to comment
Share on other sites

What is your OAL?  When you say they do not fit properly in the EGW...how so?  Picture?

 

The EGW I have doesn't have much, if any, throat & leade.  Your bullet ogive might be touching the inner rim where the case mouth headspaces. Load a few shorter and see how they check in the gauge.  If that checks out then you've found the cause & it's a non-issue.  In my EGW the cases stand proud, almost a rim-width high....and all plunk/spin in my gun barrels.  I know this so I'm not trying to load shorter to load for the gauge.  The gauge will still catch other issues like split cases, bulged cases from 9mm Major, etc.

 

Plunk & spin the 'failed' rounds in your barrel.  If they're good-to-go then there's not really an issue.

Link to comment
Share on other sites

If your resized cases fit the gauge, and then when you have seated and removed bell, and now they don’t fit your bullet profile is the problem. You can prove this by pulling bullet, and if your case still fits it’s the bullet. You can also insert case backwards, and if it goes in about a 1/4 of an inch then case bulge is not the issue. Take a reloaded round and if it fits your barrel ( passes plunk test ) then see how much it sticks up above gauge. So now you know that what you can get away with and still fit your barrel. Your bullet is keeping the round from passing. You could also shorten oal until it’s fits gauge. Some people throat the gauge so your bullet profile fits. A lot of manufacturers make gauges to minimum sammi chamber specs. They use the same reamers used to cut barrels to also cut gauges. The best gauge is a maximum case gauge. It’s sized to maximum case sammi dimensions. Those dimensions are smaller than minimum chamber dimensions. So a round that passes a maximum case gauge has to fit a chamber that is cut to minimum chamber dimensions.

Link to comment
Share on other sites

It’s your bullet profile that’s not letting the case fit to flush. You either have to get a different profile or shorten oal till it no longer keeps case from fitting flush. You can sharpie coat bullet and see where it’s hitting in the gauge.

Link to comment
Share on other sites

19 minutes ago, Jkp1987 said:

OAL is 1.142 and I measured all the cases from mouth to base at .747 +/- .002. I will send a pic this evening. Thank you for the input

 

Yes, please send a picture of the round failing the gauge.  But, from what you have described the 'problem' is actually not a problem at all.  It's just the case gauge isn't allowing for the bullet profile/ogive. Berry's don't have a fat ogive like a lot of cast 9mm do.  Your OAL is legit if it plunks & spins in your barrel.  If it were too long then that could be an issue or if it were too short then that could be an issue too because then the base of the bullet could be pushed down to where the 9mm case walls thicken and the you really could have an issue caused by bullet seating deep and bulging the case......but, that's usually seen with heavy bullets (which are longer) having to be seated short. 

 

We'll look at the pictures you post but for now I'd say you don't have a problem if the 'failed' rounds plunk/spin in your barrel.  Just mentally note how they gauge and realize that it's fine.  Don't get caught up in trying to load ammo and determine OAL for the gauge, because you load ammo & determine OAL for the gun.

Link to comment
Share on other sites

Bullet profile is the most obvious answer, but there might be another cause.  If the case was belled too much, the crimp die may not remove all of it, causing a little bulge around the case just below the case mouth.

Link to comment
Share on other sites

Since some of your reloads fit the gauge, I doubt it's the bullets...  Have you tried switching the rounds that sit high into another position on the gauge?  See if they fit correctly in a different hole.

 

Measure the crimp at the top of the case...  Should be (two times case thickness plus bullet diameter)...  Make sure all of your crimps measure the same.

 

Link to comment
Share on other sites

Yeah, to go from flush to sticking up that much is a fairly big difference. 

See @RaylanGivens suggestion above about putting them in different holes.  Also, put some that fit flush into the holes that are standing proud.  Are the gauge holes clean? 

 

You said you used once fired brass.  Do you know where it comes from and how it's processed?  The reason I ask is because if all the information I had was based on seeing that picture I'd say those problem cases are from 9mm major that weren't roll sized.  If a 9mm major case is swelled out closer to the base and not roll sized, your resizing die might not reach down that far.  FWIW, on my de-capping/resizing die, I set it to touch the shell plate then backed it off 1/4 turn.  It maximizes it's effectiveness but it's not impacting the plate each cycle .

Link to comment
Share on other sites

You said in your 1st post that your resized cases fit the gauge. Then after seating and crimping that they don’t.  This points to either your not removing the bell, or something is amiss with the bullet. Either the profile, or the oal is off. Sharpie the bullet and see if it’s in contact with gauge. Look at a sammi 9mm drawing and check your measurements against those specs. Your picture shows some rounds sitting proud by rim thickness or a little more. This is usually caused by case bulge due to being fired in an unsupported chamber like Glocks. This is resize problem and usually fixed by a EGW u die. Turn your round backwards in gauge, if no bulge it will go in at least a quarter of an inch.

Link to comment
Share on other sites

7 hours ago, Jkp1987 said:

OAL is 1.142 and I measured all the cases from mouth to base at .747 +/- .002. I will send a pic this evening. Thank you for the input

The OAL is probably your problem.  1.142 is  long for a 115gr RN bullet.  I'm loading 147gr bullets to 1.120.

Link to comment
Share on other sites

If I flip cases over they fit in over half way(pic below)

 

So I "sharpied" A round that doesn't fit and one that does. (Pic below. Case on left doesn't fit). Hard to tell but there may be loss of ink at case mouth. 
 

the non fitting case measures .380 at mouth; .380 mid case; and .386 at base. 
 

the commercially processed case that fits measures .377 at mouth; .383 mid case; and .386 at base
 

so I guess I should crimp more...

 

 

 

1E13B0FF-ECD1-4488-83B6-AB21D408EF09.jpeg

A87CA22C-AD14-40AC-BD04-B44EFED3AD2B.jpeg

Link to comment
Share on other sites

@Jkp1987, as you determined, try a little more crimp first.  EGW makes a tight gauge.  0.380" is what a fired case should measure at the mouth.  0.377" to 0.379" should be a good crimp for plated.  Increase your crimp slightly and then see if the gauging issue goes away.  Then pull a few of the rounds and inspect where the bullet was crimped.  It should have no line or just a faint line.  You can over crimp jacketed bullets and get away with it but you don't want to over crimp plated or coated bullets or you can have leading and accuracy issues.

Link to comment
Share on other sites

What I see for your pics are two things, the crimp is rubbing and the bullet seems to be hitting the rifling. 
 

Remember 9mm is tapered so inserting them inverted means nothing. 
 

While I tend to not emphasize crimp sizes mine are always about .378.

Link to comment
Share on other sites

1) That guage is notoriously tight, I would ditch it. I think it also checks OAL, which is pretty useless. Search the forum, I believe some people have drilled that part of the guage out.

 

2) Make sure the sizing die contacts the shellplate when the ram is fully extended (no gaps).

 

3) Your crimp should measure aporoximately .377 - .379 at the case mouth.

Edited by 4n2t0
Link to comment
Share on other sites

It does look like the mouth of the case that doesn't fit the gauge has rubbed the ink off...  I shoot a lot of Berry's plated 115gr bullets and use a .377 to .378 crimp...  I use all the same head stamp...  You might not get that tight a range of headstamps with range brass, but I'd go a bit smaller than what you're using now.

 

Another thing to consider...  It's possible that some of your bullets are pressing into the case slightly crooked...  A standard 9mm RN bullet doesn't press very far in to the case...  It's easier to get one crooked than a 147 or some other longer bullet...  Roll one of the bad rounds on a flat table and see if the point moves.

 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...