Semi-tight bolt close on handloads

megastink

Well-Known Member
Joined
Apr 23, 2011
Messages
955
Location
Southeast PA
So I'm pretty perplexed with this one… I have a 243 Win that I built out of spare savage parts. I had four boxes of different factory loads (Winchester, Hornady, and Herters) that I shot out of it. All of them grouped very well, and all of them fit nicely into chamber without any resistance on closing the bolt (remember this part for later. So, I took some of the Winchester once fired cases, prepped and seated some 87gr VLD Hunting pills I had laying around.

Now these cases were FL resized, trimmed to spec according to Hornady's manual, and measured with calipers and an LE Wilson case gauge. I used a Hornady OAL gauge, and seated the bullets .020" off based off of the ogive.

The new rounds chamber, but there is a slight resistance when closing the bolt. It still closes, but certainly takes a bit more force than the factory loads.

I have since measured the seating depth vs the factory ammo, and the VLD's are seated just a little deeper vs the factory ammo.

8BE52F0C-6203-4FFF-9329-0909D7F57C66.jpeg
8C868D8D-4589-407F-BBE6-D776FB49DCD4.jpeg

I also measured the once fired cases vs a prepped and primed case, and the prepped cases are just shy of the fired ones.
8C9C84AD-E0B7-4A7D-9C7C-13C9718C64A2.jpeg
5AAD6291-6257-4880-A958-B1F4089239B3.jpeg


I'm just curious what I did wrong. Am I ok to shoot these with the semi tight bolt?
 
Since you have all the fancy measuring tools there. Did you measure from the datam line of the cartridge to the base? I am willing to bet that during resizing you have lengthened that dimension.
As you resize the brass it reduces the Dia and that brass has to go some where and so the length grows until the shoulder pushes it back. If that is the case then you simply need to lower your die a little until you get about .002 set back on the Shoulder with a Hornady headspace gauge.

Meant to say that it will not hurt to fire them and resize latter since you already have some loaded.
 
Also, if using different bullets, unless you measured where the new bullet contacts the lands, you could actually be into the lands. I have measured different bullets in the exact same chamber, and found significant different CBTOs where they touch lands. .020" jump for one bullet might be jammed for another.

Note the differnces in CBTO between different bullets due to to ogive shape.
20221104_210210.jpg
 
I agree Wedgy, Check a sized case without bullet. If you used a die with an expander button, Sized the case then trimmed the case. If there is to much drag on the expander, It could pulling on the neck and pulling the neck/shoulder junction forward.

Size a case in the die, Black the shoulder neck and case in front of the extractor ring with a magic marker or candle soot and carefully insert in chamber and lock bolt into battery may tell the problem. Should show contact of case with chamber.
 
Agree with above comments. You have to take a measurement off of the shoulder of the case, not the overall case length.

Before I had tools to measure this, I would lube the case, try sizing, then try to chamber. If it still chambered hard, I would turn my seating die down in a little more, resize again, and chamber again. Repeat as needed until the case chambered easily.

I now have the bullet comparator set from Hornady. Like yours. If you use the .30 cal bushing you might be able to stick your empty 243 casing neck into it. Then you could measure an empty casing vs factory new. That's basically how I measure it.

Presently, I basically do it the way I started out... Just barely sizing it enough for it to chamber easily. To me, it doesn't "really" matter what the actual shoulder set back distance is... I figure if I go until the case just barely is sized enough that it chambers easily, my brass shouldn't be over worked and have good case life.
 
Did you bump the shoulder back? For me it's always 1 of 2 things.. either the headspace (shoulder to base) or primer not seating. I solved the primer issues with a Sinclair pocket uniformed. All primers are now .002 below bolt face. The I use a Whidden universal bushing set to measure bump back.
Good luck
 
I know it's been a while, but I got the courage to fire these rounds today. Yes, it's been a year, but life happened and today, I got to do some shooting. The rounds which were tighter than usual to close the bolt on fired just fine, no pressure signs. In fact, they grouped pretty **** good too.
 
I know it's been a while, but I got the courage to fire these rounds today. Yes, it's been a year, but life happened and today, I got to do some shooting. The rounds which were tighter than usual to close the bolt on fired just fine, no pressure signs. In fact, they grouped pretty **** good too.

You probably are not bumping the shoulder enough. But you must have been busy, cause it's 2024 so it's been 2 years.
 
Top