Bullets are keyholeing on target

[Bench]

I'm getting a ragged "keyhole" instead of a clean round hole in targets. What would cause a bullet to 'tumble' instead of spiral? This is with my reloads and not with factory loads so I'm assuming that it isn't the gun, a 92FS. The loads in question:

9MM

147 gr. Precision FN

2.6 gr. Titegroup

OAL 1.058

CCI 550

Crimp: .377

 

1.) I'm going to up the load to 3.2 TG first to see if that will have an effect. Also to make PF(!).

2.) What effect will a SLIGHTLY tighter crimp have on bullet flight? Two dummy rounds crimped to .376 seem to plunk perfectly.

 

Any other considerations here that I may be missing?

 

Thanks!!

[rowdyb]

1. you need enough powder to get enough fps for the bullet stabilize. change just one thing at a time. do this first.

2. if you mar the outer surface of a bullet by reducing the bell to much you will get erratic grouping. more crimp seems to only be an answer for semi autos when you're developing a load and trying to get them to pass a case gauge.

[Frank705]

Well I think your move to increase the powder load is a good first step. I load 2.8 of TG with 165 Gr RN and 3.2 with 147 Gr RN both from Xtreem. 

[zzt]

Your bullets keyhole because they are not traveling fast enough to stabilize.  The faster load you plan will help.  I doubt you will notice anything by making the crimp .001" tighter.  As a general rule, I only crimp enough to prevent bullet setback.

[Bench]

12 minutes ago, rowdyb said:

1. you need enough powder to get enough fps for the bullet stabilize. change just one thing at a time. do this first.

2. if you mar the outer surface of a bullet by reducing the bell to much you will get erratic grouping. more crimp seems to only be an answer for semi autos when you're developing a load and trying to get them to pass a case gauge.

We'll see what happens with the increased load first as you suggest. Then see what the groupings are. Thanks!
 

[Beef15]

That's a coated bullet right?

Like others said, probably too slow.

3.0-3.3 is a pretty standard range for Titegroup with that weight cast/coated bullet. I don't understand why but my Lyman book lists way lower, like stock sprung gun don't function low.

Determine OAL by plunk test, 1.058 is very short.

0.376/0.377 "crimp" should be in the ballpark, maybe a touch tight but not enough to matter.

Your magnum primer shouldn't hurt anything but is unnecessary.

 

In light of the short OAL and magnum primer I'd probably bump to 3.0 chrono, work from there.

 

Don't know how many you shot, but check the bore for leading or other heavy fouling.

Edited May 1, 2018 by Beef15

[Bench]

15 minutes ago, zzt said:

Your bullets keyhole because they are not traveling fast enough to stabilize.  The faster load you plan will help.  I doubt you will notice anything by making the crimp .001" tighter.  As a general rule, I only crimp enough to prevent bullet setback.

Crimp was suggest to me by another shooter but I think I may hold off changes there until I see what the increased load does. Thanks.

[Bench]

Just now, Beef15 said:

That's a coated bullet right?

Like others said, probably too slow.

3.0-3.3 is a pretty standard range for Titegroup with that weight cast/coated bullet. I don't understand why but my Lyman book lists way lower, like stock sprung gun don't function low.

Determine OAL by plunk test, 1.058 is very short.

0.376/0.377 "crimp" should be in the ballpark, maybe a touch tight but not enough to matter.

Your magnum primer shouldn't hurt anything but is unnecessary.

 

In light of the short OAL and magnum primer I'd probably bump to 3.0 chrono, work from there.

Yes, they are coated. Like you I've been using; the Lyman's book and they start out at 2.6 TG and don't go much higher. The dummy rounds plunk well at 1.058 and .376 crimp. I'll see what happens with the increased load first then as suggested above if the groupings are off then fiddle with the crimp. Thanks!

[manolis]

I solve my tumbling problems with a much slower powder ( sp2 for examble).

It was so simple. No matter if the front was undersized ,or soft or what ever.

BTW i think that 2.6 gr. of Titegroup is too little , not fast enough to stabilize .

Manolis

[ddc]

I don't shoot TG but I've loaded both Alliant Sport Pistol and Prima V which I understand to have similar charge weights and are often compared.

I don't know if my guns would cycle with a 2.6 gr load of either under a 147.

The lowest I ever went was 3.1 with Prima V and a Blue Bullet 147 and while it was very soft shooting it was just at or under minor power factor.

[Bench]

28 minutes ago, manolis said:

I solve my tumbling problems with a much slower powder ( sp2 for examble).

It was so simple. No matter if the front was undersized ,or soft or what ever.

BTW i think that 2.6 gr. of Titegroup is too little , not fast enough to stabilize .

Manolis

Another lesson in reloading...data books don't have all the information needed....my gun, my reloads through a chrono is the best data.

[Bench]

2 minutes ago, ddc said:

I don't shoot TG but I've loaded both Alliant Sport Pistol and Prima V which I understand to have similar charge weights and are often compared.

I don't know if my guns would cycle with a 2.6 gr load of either under a 147.

The lowest I ever went was 3.1 with Prima V and a Blue Bullet 147 and while it was very soft shooting it was just at or under minor power factor.

Interesting to hear of comperables in powders. I'm still too new to pistol reloading so sticking with TG for now and get this load nailed down for PF and accuracy. Thanks.

[ddc]

7 minutes ago, Bench said:

Interesting to hear of comperables in powders. I'm still too new to pistol reloading so sticking with TG for now and get this load nailed down for PF and accuracy. Thanks.

 

I think that is a very good idea. Good luck!

[Bench]

2 minutes ago, ddc said:

 

Good luck!

LOL, hopefully with my gun, my loads, through a new chrono that's coming I'll be able to eliminate the "luck" and be "good".

[rishii]

My gun keyholed with 147s, I solved it by going to a lighter bullet

like they posted above, I figured it wasn’t going fast enough to stabilize, and rather than  upping my powder charge, I went with a135 gr bullet that I pushed to 1000fps, it was still soft shooting, made pf easily and grouped well

 

[ddc]

2 hours ago, Bench said:

LOL, hopefully with my gun, my loads, through a new chrono that's coming I'll be able to eliminate the "luck" and be "good".

 

Having a chrono is critical. I have no idea why it took me so long to buy one.

 

It should be a part of the initial purchase along with the press, powder, bullets, etc.

[Don_B]

Without an chrono everything is just a guess. 

[IGOTGLOCKED]

You have received good advice ^^^

As an fyi - I have shot a lot of (9) Hi Tech coated Acme (great bullets) 147 RN with 3.2 of TG. The result seemed to be leading.  TG is too hot for coated bullets,  it burns the coating off the back. Several months ago I switched to Alliant Sport Pistol which Alliant claims was developed for coated bullets. No more leading issues so far, much cleaner, and softer.

Cheers!

[HesedTech]

You’ve gotten good advice. 

 

One last question, what kind of crimp die are you using?

 

While your TG load is too low for USPSA (I shoot 147s and use TG) tumbling is most often a function of crimping and damage to the bullet where it sets in case. 

 

I use a Dillon crimp die and never worry about the actual crimp size. (The reason is because when using range brass the case wall thickness varies from brand to brand and it is difficult to get a single crimp number that works.) What I do is this:

 

1. Load a few test rounds (no powder or primer) at the correct OAL for my gun. 

2. Make sure it plunks in barrel and Hundo gauge checker. 

3. Unload/pull bullet and check for crimp ring/dent (there shouldn’t be one) and damage to base and coating. Make sure you do this with multiple head stamps/brands of brass. 

4. If it passes the above good to go, load up live rounds for chrono and range test. 

5. If it fails the crimp inspection, after checking multiple different head stamps, loosen crimp and run some more test rounds. 

 

The goal is the least amount of crimp that will hold bullet in place and will case gauge; the 147gr 9mm has almost zero chance of setback due to tapered brass case and especially because the 147 is really long and set deep in the case. 

 

Damaging the base of a subsonic bullet has a far greater effect on how it flies than any to the nose.

 

Have fun and let the readers know what worked for your process of reloading. 

Edited May 1, 2018 by HesedTech

[HesedTech]

6 hours ago, Bench said:

Yes, they are coated. Like you I've been using; the Lyman's book and they start out at 2.6 TG and don't go much higher. The dummy rounds plunk well at 1.058 and .376 crimp. I'll see what happens with the increased load first then as suggested above if the groupings are off then fiddle with the crimp. Thanks!

 

I just noticed the length, is that really what you are loading at?

 

If so your problem is highly likely the base is getting swaged down by the case and may be undersized. Definitely pull some bullets and check the size. 

 

I shoot Tanfoglio, my son CZ, using Blues and Eggleston 147s the nose profile limited our length to 1.08 and with that I had to be picky with brass. CBC was definitely a no go and any with that dashed ring around the outside, Aquila and FC I believe, also failed. After running over 15k of those we switched to Acme 147FP for 10k and it loaded far easier with zero head stamp issues (yep CBC loaded fine) with a length of 1.13-1.14. The difference is in the nose profile. 

 

It takes a some practice and trying of different brands and shapes of bullets to find the one which works best for you.

 

again have fun, this is a hobby. 

[Bench]

3 hours ago, rishii said:

My gun keyholed with 147s, I solved it by going to a lighter bullet

like they posted above, I figured it wasn’t going fast enough to stabilize, and rather than  upping my powder charge, I went with a135 gr bullet that I pushed to 1000fps, it was still soft shooting, made pf easily and grouped well

 

And were you able to make PF with 135's?

[Bench]

3 hours ago, ddc said:

It should be a part of the initial purchase along with the press, powder, bullets, etc.

Well said, some one should offer a "package deal" LOL

[Bench]

3 hours ago, Don_B said:

Without an chrono everything is just a guess. 

And I'm tired of guessing!!

[Bench]

1 hour ago, IGOTGLOCKED said:

You have received good advice ^^^

As an fyi - I have shot a lot of (9) Hi Tech coated Acme (great bullets) 147 RN with 3.2 of TG. The result seemed to be leading.  TG is too hot for coated bullets,  it burns the coating off the back. Several months ago I switched to Alliant Sport Pistol which Alliant claims was developed for coated bullets. No more leading issues so far, much cleaner, and softer.

Cheers!

The comment about CLEANER sounds intriguing. I'll have to look it up to see where it is in the burn rate charts. Just like a sage said on this forum 'heavy bullets, fast powder...."

[rishii]

Minor, easily

3.8 of w231 averaged 130PF

4.0 of w231 averaged 135PF

both of those out of a S&W 5906