lead bullet seating depth

[mohunter55]

How do you tell the depth that you want to seat a lead bullet? For instance, I'm working with 40 s&w and I want to use Missouri Bullet Company's 170 grain wadcutter and I have data that was sent to me from Alliant. I'm not sure if the data is safe yet, as I have not had a chance to compare it to anything else...but assuming i use the below data (which is actually 175/180 grain data...not 170), how do i tell OAL? They did not send any?

175/180 gr lead
Bullseye powder start 4 grs Max 4.9 grs
Unique powder start 4.7 grs Max 5.5 grs
Power Pistol powder start 5.7 grs Max 6.5 grs

also, how do you tell OAL for other loads which use the same weight, but a different bullet manufacturer, for instance, say i have missouri bullets and I use data from lyman for 175grains? They have 2 175grain bullets, one is 1.1ish and the other is 1.25ish if i remember correctly for OAL.

 

[MichaelK]

HI Mo
Basicly you have to facter in three things.

First, the loaded rounds most fit in your chamber. You can determine this rather easily by taking the barrel out of your pistol and inserting a FIRED case with your bullet sitting in its mouth. Set the bullet so it is barely inserted into the case mouth. Slide the case/bullet into the chamber so that as the bullet starts to touch the rifling it will shoved back into the case. Carefully remove the case/bullet and measure its OAL with a caliper. Repeat this several times till you're sure you're getting an accurate number. With my pistol and Lyman's 175 TC it's 1.375".

Second, you have to determine what is the longest length that will fit in your magazine. Loaded rounds with a length of 1.375" will NOT fit into the magazine of my pistol. The longest length the magazine will accomidate is about 1.175", so at stage two the OAL must be less than 1.175".

Third, you must determine what is the optimal length that will FEED out of the magazine. In my case, 1.175" was still too long, failures to feed with every round. I finally determined for MY pistol the optimal length with Lyman's 175 grain TC was 1.145". At that point I began load development and determined the powder charge of Blue Dot that gave me the best accuracy. I ended up with a 175 grain hard cast load with 9.5 grains of Blue Dot at an OAL of 1.145".

Please note that these numbers were developed for MY GUN! This load might or might not be the best load for your gun! Do the same level of load development with your pistol and you'll produce a very accurate, well performing load with any bullet of your choice.
Good luck,
Michael

 

[squarles67]

Very good advice above

FWIW I load that bullet to 1.132 for my M&P .40

 

[mohunter55]

thanks for the advice, I have a question regarding your method. How do you know if the starting charge you are using is safe to use with how deep the bullet is seated? Thats what I am really worried about is seating a bullet to deep and increasing pressure to much.....is this something you dont have to worry about when using starting charges?

 

[mohunter55]

today i contacted Ramshot regarding the below data:

40 S&W Lead Bullet Data:
True Blue: 170 LSWC Min 5.9 - Max: 6.6 OAL 1.130

Silhouette: 170 LSWC Min 5.5 - Max: 6.1 OAL 1.135

I asked if i can load these to 1.125 to fit my loan wolf barrel. Their response was:

You can use the same data for the 170gr SWC bullet @ 1.125"

All they said was to start with starting grains. So, what I am getting from this, is that it is fine to adjust OAL shorter as long as I am using starting grains, and not setting it to a rediculously short OAL. Does this thinking sound right?

 

[rcmodel]

Yes.

The only time shorter seating will cause a dangerous condition is if you are already dangerously close to a MAX overload.

As a matter of fact, seating .010" deeper then listed by the data is not going to ever create a dangerous overload unless it already was one.

You could easily have half that much difference from one round to the next in a batch due to seating OAL variances and bullet ogive variances.

rc

 

[mohunter55]

Thanks RCModel, as you usual you have answered my question perfectly. I think a lot of my confusion in reloading has came from fear of OAL. I should be good to go now, as i have yet to venture away from starting greats yet. All ive really be doing with reloads for all my calibers is experimenting for light target loads anyways.

 

[LiveLife]

rcmodel:
As a matter of fact, seating .010" deeper then listed by the data is not going to ever create a dangerous overload unless it already was one.

You could easily have half that much difference from one round to the next in a batch due to seating OAL variances and bullet ogive variances.

+1. If you reload mixed straight walled pistol head stamp range brass, you will see variations in OAL. If you want to eliminate this variable for more accurate load testing, you can sort by same head stamp and similar length cases after sizing.

For 155-180 gr 40 S&W bullets, I normally start out my dummy round with 1.125" OAL and adjust OAL IF I have any feeding/chambering problems.

 

[mohunter55]

shot my rounds today. I went with 1.120 and 1.125. All functioned perfectly through my glock 22 with lone wolf barrel and MBC 170grain LSWC. Not one jamn and none showed any signs of pressure. I could not tell a difference in either of the two rounds, so i think i will go with 1.125 for now, just to give a little leeway

 

[Hondo 60]

Reloading Manuals are PRICELESS!! Get a couple & you'll have all the info you need.
Including OAL.

 

[mohunter55]

Yurko, I already have ABC's of Reloading, Speer, Hornady, Hodgdon's annual manual, and Lymans. All have been a little light on the advice with OAL. They make it clear that you can load longer, but they dont say a lot about seating deeper, other than that it will raise pressure drastically in some calibers. After a call to hodgdons and some advice from you guys, that question has been answered for me.

Thanks

 

[LiveLife]

mohunter55, great job. I love happy endings.

Now you get to load test for accuracy comparison with incremental powder charges (my favorite part of reloading).

Often, accuracy increases as powder charges are increased for better powder burn and more consistent shot groups.

 

[mohunter55]

thanks bds, now that i got this down. My next task is to figure out loading wadcutters in 38 special. I think i almost got it figured out. Brad at missouri bullets has been very helpful. I almost bought the wrong bullets, didnt realize they sell them in .357 and .358. Since im not using them for PPC or any competition ill be going with the .358. I'm hoping to get a nice light load so my wife can finally shoot my 642 s&w.

 

[LiveLife]

You should be able to get a light 38 Spl load with Bullseye, but many here recommend Trail Boss for light recoil loads - just might be the ticket for your wife.

Also for 180(170) gr 40 S&W, 3.8 gr of W231/HP38 is the lightest recoil training/practice load I use that recoils less than 9mm loads - your wife may enjoy shooting your 40 too. If you can't find W231/HP38, Green Dot is a good substitute powder.

Reloading and shooting is a fun hobby, but so much better if you can get your wife excited too.

 

[rcmodel]

FWIW:
Case length has no effect whatsoever on OAL of the loaded round.

Case length variation effects the amount of crimp, but it does not / cannot effect OAL at all.

rc

 

[LiveLife]

Nice catch rcmodel, and I stand corrected.

If you reload mixed straight walled pistol head stamp range brass, you will see variations in OAL

I meant to say variations in case lengths, not OAL.