Excessive Leading on Target Loads

[fredj338]

It will depend on the brass, but measure the expander, if it is 0.355", you may be fine with a harder alloy bullet. The other issue is bullet alloy. At target vel/pressures, you can try a softer alloy, see if it bumps to fill the chamber throat. Too many think harder alloy is better, but you rarely need to go beyond 12bhn unless shooting the magnums above 1200fps.

 

[SW CQB 45]

I will measure my expander but I have a couple of older slugs that have been sitting around.

I dont recall the weights….thinking 125ish

.3565" and .357"

I better slug my other two match barreled 9mm 1911s. I guess being a 45 shooter for so long and the venerable .452" diameter served me so well in all my guns that when I switched to Nina, the regular slug was also selected.

 

[AveragEd]

For what it's worth, which might not be much, I once tried .355", .356" and .357" 125-grain cast semi-wadcutters in my .38 Super over the same charge of AutoComp powder. The .355s were less accurate than the other two, for which accuracy was the same (good), and none left any leading behind.

Ed

 

[SW CQB 45]

small Dillon expander die

to add even more evidence…..my Dillon 550 expander is .353"-.354".

I have another one…I need to dig it out and measure.

Well Hell......my other one measures exactly like the other.

Does Dillon or anyone else make oversized like .355 or .356 for 9mil in a 550B?

 

[venomballistics]

One thing that I used to do was intentionally do a half hearted job of cleaning the bore.
When the bore is black as original sin, it tends to shun lead.
Also, a bore mop saturated with grease between the first 6 rounds helped to get a pristine bore started.

 

[SW CQB 45]

Well I loaded a test slug using a old Superior Cast .357" 125 grain RN. I verified .357" diameter and loaded and light taper crimp. I pulled the slug and 're verified it is still .357". Yay!

I loaded 100 rounds and decided to use 4.3 WSF and set the 125 RN at 1.080". Based on the books I used as reference......close to 1000 fps.

I also checked my two other match 9mil 1911s and they both slug at .355".

thanks for all the advice

 

[mtgianni]

Based on your pictures the bullet is not undersized for the bore. The rule of thumb is that leading in the muzzle end is running out of lube, in the chamber end fit. Since the base size is larger than the bore, the bullet is either entering the bbl misaligned, passing through an uneven bbl throat or scraping the shoulders some other way. I believe most commercial lube is too hard for my applications and best suited to stay in place during shipping.
Your solutions seem to be to really examine the bbl throat if that is where your leading is happening or continue with the loads you have knowing that something is causing the leading. Switching to a less swc profile and a more rn one might be worth a try to see if the bullet is still shaving. .

 

[SW CQB 45]

what is baffling to me, the accuracy is still at a acceptable level. but I wonder if this was pushed further (to like 50 yds) if accuracy will start to suffer.

Anyway….these little guys are ready to go. I hope to test this weekend. What I don't like about these rounds (RN)…..

we shoot for points and the SWC design shoots a cleaner, bigger hole. I am going back to 45acp next year to get the bigger hole advantage.



this was shot with my other Springer but using the same 115 SWC rounds. if the caliber would have been .45acp, I would have scored 500!!!!

 

[M29since14]

Try it out at 50 yards and let us know. I have never shot my 9mm lead loads farther than 25 so I can't help with an answer but your question does make me wonder. Weather permitting, I think I will try it myself before it gets too cold to hold still. (It's coming. )

Anyway you cut it that is nice shooting! Your gun should do even better with the larger bullets.

 

[rwsmith]

this was shot with my other Springer but using the same 115 SWC rounds. if the caliber would have been .45acp, I would have scored 500!!!!

I don't think I'll be sneaking up on you.

 

[SW CQB 45]

I went to test 50 of the new reloads on Friday but not in the best of conditions and it showed in my marksmanship.

I had to zero a couple of patrol rifles with a co-worker and it took some time as we had to share the range with another agency.

by the time I was able to sneak out the Springer, it was 1130 hrs and I was starving and needed to get to my office, so my mental process was not all there.

My first 18 rounds were fired at the 7 and 15 yd line and was aiming dead center X when I forgot I have my sights set for a 6 o'clock hold at the X and 10 ring.



The remaining rounds were fired from the 25 yd line and was not happy with my performance. I am always the student of marksmanship and there were many rounds here that got away from me. When I started my press, before the hammer fell, I moved…and it shows. However I do think the accuracy potential is there with these rounds and plan to use them in my match this weekend. I promise to do better this weekend.

Sunday, I will tear apart the gun and check for leading.

remaining rounds fired from the 25 yd line.

 

[SW CQB 45]

Follow up on barrel cleaning

Barrel clean up today was a non issue with .357" slugs. after a couple of passes with solvent, bore brush and thin oil for protection…no traces of lead.

YAY!

I need to order some .357" 125 grain SWC slugs.

thanks to all

 

[Bugkiller99]

This thread has been a good read. Well done detective work by the OP with a little help from the forum.

 

[M29since14]

Glad to know the larger slugs are working. Clean your barrel every time you shoot more than a few rounds, just to be sure you don't get any hard to remove accumulation right in front of the chamber. I have been shooting .357 and .358 lead bullets in my 9x19 Kart barrel now for almost two years and have had great luck with them. I don't know why I didn't do it years ago.

 

[gwpercle]

Barrel clean up today was a non issue with .357" slugs. after a couple of passes with solvent, bore brush and thin oil for protection…no traces of lead.

YAY!

I need to order some .357" 125 grain SWC slugs.

thanks to all

GREAT !
.357 is what works in my 9 mm's also . I have tried several different weights and designs and .357 is the magic number. It didn't matter if it was a SWC, truncated cone or round nose. .357 and not real hard (wheel weights and pure lead 50/50 works best)
Fit is very important with cast and leading in fact a hard undersize bullet will give you trouble every time.
Gary

 

[BruceM]

It's good that you solved your problem by using a bullet .001" larger in diameter. With the .356" groove diameter of the barrel, you obviously were getting gas blow-by which caused the bore fouling. Almost invariably, lead fouling is caused by improper bullet fit or insufficient lube. Very seldom is it caused by bullets which are "too hard". Cast bullets can be unnecessarily hard but if they fit correctly, are never too hard and cause leading. If you are in the trick bag because of a particular gun's mechanical mismatches; that's a different issue.

Bruce