Bullet Setback

[Sven]

Today shooting some light loads in 45 ACP - this is the old quantico bullseye load larryw introduced me to:

4.3 grains of WST capped with a 200 gr SWC plated.

In the course of fire I had many failures to extract due to - I believe - the strong spring I have installed currently for +P loads.

On one particular failure to chamber, I performed a clearance drill and it took two racks of the slide to extract. Finally the round falls out and - thank goodness I looked at it - the bullet was seated deeper in the case, probably to the powder.

Talked with larryw today and he thinks we should check the length of my brass - crimped light?...

..wonder what would have happened if I'd shot that round? Would it have felt like a double charge? Would I have even noticed?

-s

 

[dodgestdshift]

Sven:

What defeats bullet setback, is your sizing of the case. I doubt that crimp alone especially since it is a taper crimp for 45 ACP will hold the bullet enough. The heavy spring will obviously put more pressure against the bullet when feeding. My questions to you are:

1) How many times had the cases been fired?

2) What brand of cases were you using?

3) Check the sizing operation for this load. Could they have been improperly sized?

4) Did you overbell the case to ease bullet seating?

5) Is it possible to over crimp a taper crimp and cause looseness? It is possible with a roll crimp.

Take the remaining loads and try to push the bullets farther into the case by pushing them against a flat surface. Maybe only that case was defective. If more cases fail the push test, maybe you need to change case brands.

The pressure question cannot be answered by anyone, With less air space you will get higher pressure. How high, I have no idea, but I would not shoot that round.

 

[HSMITH]

What defeats bullet setback, is your sizing of the case.

This is gopsel truth^^^^^^. You can crimp until you buckle cases and it won't help, it will hurt eventually as you swage the bullet down with the crimping. Measure a bullet pulled from the loads you shot today, compare it to a new bullet. You probably are overcrimping, most reloaders do. Look at the diameter of the bullets and the diameter of the sized cases. You need 2 thou of "press fit" for the bullets to be held securely in the case.

 

[larryw]

Brain dead when I saw you yesterday...

Case tension holds the bullet in 45. Bring that round by and we'll look for cracks or other flaws in case and measure bullet.

As it stands, crimp die is set to just remove bell.

 

[Jim Watson]

Plated bullets seem particularly affected by setback.
They have a slick copper surface and a soft lead core, at jacketed bullet diameter.
The SWCs I tried looked like #68 SWCs but were really not the same shape and did not feed as smoothly even when they did not set back.
Light weight jacketed bullets are nearly as bad.

I have tried several options including, three different sizers, three different expanders (including a .44 which flared but did not expand .45s at all), and two crimps. None were fully effective.

I am now loading 185 gr JHPs on hand with a cannelure in the brass at the base of the bullet. Those suckers do not set back, but it is an extra step in the loading that cannot readily be incorporated into a progressive loader.

I **think** Federal brass may be enough harder and thicker to give adequate bullet pull. I am accumulating some by sorting and will give it a try.

Mostly I will use up the 185s on hand and then stick to cast SWCs and 230 jacketed.

 

[larryw]

Jim, some plated are as you state, but Sven's using West Coast Bullets 200SWC (looks and feeds like a #68 to me); they have a very hard core and thick plating. He's also loading at my press using my existing setup and I've run about 20K just like his and never had this problem. I'm betting on the brass.

 

[Jim Watson]

Brass?
OK, what's his, what's yours?
Remington used to be terrible. I find it usable now with cast. I had setback trouble with Raniers and Remington bulk JHPs in WCC and TZZ military, WW, Speer, and RP commercial. As I said, I am now accumulating some Federal to try more thoroughly.

How about the guns & magazines?
Maybe yours feeds more smoothly than his, without a hard drive into the ramps to set the bullet back.

It has taught me I don't know as much about reloading as I thought.
I hope we learn something here. More knowledge is better, and if setback can be simply fixed it will improve flexibility and performance. But less trouble and hassle save time, and that is what counts. Right now that looks like 200 gr cast SWC and 230 gr jacketed.

My FLG got me started canneluring under the base of the bullet - like some Federal and Remington factory ammo - and he has been reloading longer than I have. I designed the tool to do it in one stroke of a (single stage) press and he made it so as to save the labor of one of those roller devices.

 

[larryw]

Good points, Jim! And isn't that the truth: knowledge is often understanding how much we still don't know.

In both cases, brass is mixed. Mine is heavy on S&B (that's been loaded dozens of times), with Win second. I think Sven is heavy in Win brass, most of which is once fired. The majority of my rounds were shot from a USP Expert, but that's been sitting in the safe since my Valtro arrived, which has about 2500 of this load through it. Sven's also shooting a Valtro. I'm using Wilson 47D 8-rd mags, which load the cartridge into the chamber a bit flatter than 7 rounders do and don't bang bullet against the top of the chamber, for me 8s have always fed SWCs better than 7s. I think Sven is using 47Ds too (Valtros come with 8 round mags and I hate scratching the gorgeous bluing on those mags).

Using a Lee "Factory Crimp" die to remove the bell (.469"), Dillon carbide sizing die. When working up the load, I did the "press against the bench test" and was unable to get the bullet to move.

If there's anything wrong with this load, its the fact that the COL is short (1.235COL), but its always fed fine in my guns and the accuracy is spectacular. (see http://www.dimark.com/shooting/45X10.jpg: 10 rounds at 25 yards with an operator error called flyer, I adjusted POI to maintain POA prior to firing string).

As soon as we do the autopsy on these two rounds and examine the rest of his stockpile for similar characteristics, one of us will post a post-mortem. If its not the brass, I'm going on record right now and blaming Sven for doing something funky to my favorite load.

Using Berry's bullets, I've had problems similar to what you describe. Loading them almost felt like squeezing an over-ripe Orange with a firm skin and a mushy core. Leading in my polygonal barreled USP was bad. I almost gave up on plated bullets until the owner of a local reloading shop more-or-less ordered me to try the WCBs he stocks. Since then, I've become a strong advocate of this brand. Highly recommended.

 

[Sven]

The round with the extreme setback is Winchester brass, once fired. Never trimmed. Looks un-distressed although you can tell that multiple attempts at chambering were made by light banding on the brass near the mouth.

Another round that had a hard time cycling was examined and set aside as well when slight setback was detected - this is S&B, also once fired and never trimmed. The plot thickens.

One other detail from this session: gun (1911) was recently cleaned. I had just put 50 rounds of Speer Lawman downrange before switching to the handloads. Noted that the Speer was yielding very dirty brass with a streak down one side - looked like the chamber didn't seal or the brass didn't fully expand in the Valtro. This didn't happen with the handloads.

Anyhow, here is my theory as to yet another excacerbating factor to the original problem: PERHAPS the chamber was dirty from these first rounds... the gasses and unburned powder would escape across the top of the brass sitting in the chamber... this powder could cake on the top of the chamber, right where these SWCs where sitting nose-up upon examination.

Maybe I just need a 16# spring.

Regardless, larry and I will pull these rounds (and others) apart and report.

Thanks for the help!