need 380 auto load help for OAL

turbovr6 · January 14, 2010, 07:44 PM

I am reloading 380 auto. I am using Starline (.676")cases with Xtreme 100gr bullets which are round nose flat point. I am using Remington 1 1/2 primer with 2.6gr titegroup. Hodgdon calls for .980 inches for OAL. However, when I seat this bullet at that depth it appears the bullet is not in the case far enough to hold it securely. I measured the bullet and it is .427" long. Since this is a RNFP do I need to seat this further in like a hollow point? what is the length of a normal 100gr Round nose bullet? Mabe I can subtract the difference for better seating. Thanks

spacecoast · January 14, 2010, 07:52 PM

I have some 100 gr. Berry's plated RNHB (hollow base) bullets and they are 1.20 cm or about 0.472 inches. They would be slightly shorter than that (I believe) if they were RNFB.

**Unclenick** · January 14, 2010, 08:57 PM

0.123" deep is pretty shallow. Between .2 and .25 would be better. Try a COL of .870", and load 2.7 grains of Hodgdon Universal and work up toward 3.2 grains. Powder needs to come down a little when you seat deeper.

RidgwayCO · January 14, 2010, 09:08 PM

Suggestion... load your .380 Auto bullets so that at least .175" or more of the bullet is seated in the case, to help ensure the case has a secure grip on the bullet.

Then use this basic equation to figure your COL:

.676" (case length) + .427" (bullet length) - .175" (seating depth) = .928" (COL)

Now check to see if a dummy round loaded to this COL will function in your .380 Auto pistol. You can't really make it any longer (without adversely affecting the critical tension between the bullet and case), but you can make it shorter if necessary.

Remember that if you decide to seat more of the bullet inside the case, then the COL will be less. Also remember that any rounds you make with a COL shorter than the data you're using will require you to reduce the amount of powder used. Pressure goes up quickly in those small semi-auto cases, especially when you're seating the bullet deeper than when the test data was shot.

dfe2240 · January 15, 2010, 10:28 AM

Quote:

Also remember that any rounds you make with a COL shorter than the data you're using will require you to reduce the amount of powder used.

That brings up an interesting point. In my opinion, COL is nothing more than a general reference UNLESS you know the length of the bullet used with a particular COL and powder load. In turbovr6's case, the Hodgdon COL data has to be referenced to bullet length to determine appropriate powder load and seating depth. With respect to pressure, the controlling factor is inside case length (the distance from the base of the bullet to the base of the case) which you can determine by subtracting bullet length from COL. This combined with RidgewayCO's formula for figuring seating depth should enable you to work up your loads. Then all you have to do is hope they feed properly.

**Unclenick** · January 15, 2010, 02:35 PM

That's why the Universal loads I provided are smaller than Hodgdon's for same weight bullets at .980". I used QuickLOAD to make the adjustment. My copy of the Hornady second edition handbook, gives seating depth instead of COL. I think that is more useful information.

As I've posted elsewhere, you can rearrange the formula to give COL from seating depth or to find seating depth from COL by swapping the two as the subtracted term.

RidgwayCO · January 15, 2010, 05:22 PM

Yep Unclenick, you've gotta love QuickLOAD for working with varying COLs. It's not perfect, but it's a lot better than working in the dark...

Sevens · January 15, 2010, 08:17 PM

Quote:

In my opinion, COL is nothing more than a general reference UNLESS you know the length of the bullet used with a particular COL and powder load.

I agree, but that's exactly what I need it for... a general reference. I need repeatability. When I build a load and make it work and get it dialed in, I need to know how to make exactly the same thing the next time I wanna turn out some ammo.

Load data, published or otherwise is always going to be a guideline, not an exact recipe. But once I've developed a load that does what I ask it to, it becomes one of my recipes. And using the same components, I can replicate it any time I want.

You know how you always hear about wasted youth? How about wasted handloading youth: When I started I would make this, that or the other thing and I didn't keep a log or records... every time I went to make something it was like starting from scratch.

Boy, I learned in short order.

That's what COAL means to me -- my own reference point that I keep so I can replicate.

turbovr6 · January 16, 2010, 04:02 PM

Thanks, So the hornaday manual gives a seating depth for the 380 Auto? I think that would be more useful than OAL for a bullet that there is no load data for. I then can calculate the proper oal from the length of the bullet. Final internal volume is what is important to have correct. Not necessarily OAL. (Unless to properly feed). So what does Hornaday state for seating depth?

**Unclenick** · January 16, 2010, 04:05 PM

turbovr6 · January 27, 2010, 05:02 PM

Thanks everybody. Worked out a nice recipe and found the OAL that really works. 100gr Extreme RNFP, Rem 1 1/2, Starline brass, 3.0gr Titegroup, OAL .935". Works beautifully in PPKS.

RidgwayCO · January 27, 2010, 08:06 PM

Congratulations! There's nothing better than finding a load that works great in your firearm. Any idea what velocity those loads are producing?

Ryushin · July 5, 2014, 09:17 AM

I know I'm zombiefying an old thread, but Google brought me here. I duplicated this load and I wanted provide final numbers:

Pistol Used: Sig P238 2.75" barrel
Powder: Titegroup
Bullet: X-Treme 100gr RNFP
COL: 0.935
FPS looking for: just under 912 (95gr bullet, per Hodgdon)
Temperature: 85 degrees Fahrenheit

2.80+-.02gr:
10 shot FPS: 832 821 829 818 819 829 820 841 834 847
Average: 829 FPS

3.00+-.02gr:
10 shot FPS: 896 874 906 887 893 900 914 900 870 896
Average: 894 FPS

Wow. Perfect load. Very happy. Recoil is very mild. Wife really likes the new load. Functions perfectly through the P238.

Clark · July 5, 2014, 11:42 AM

Different 380s will do different OAL.
The longest I have is Husqvarna 1907 that will do 1.090" max.
The shortest I have is a Kahr P380 0.965" max.

Ryushin · July 5, 2014, 03:45 PM

According to the reloading manuals, 0.984 is the max COL. The flat point bullet makes it harder finding a good COL. The post by RidgwayCO really helps in this. It would be nice if the reloading manuals and sites did mention what the max seating depth was. That is probably the most important piece of information instead of using COL.

January 14, 2010, 07:44 PM	#1
turbovr6 Junior Member Join Date: January 14, 2010 Posts: 3	need 380 auto load help for OAL I am reloading 380 auto. I am using Starline (.676")cases with Xtreme 100gr bullets which are round nose flat point. I am using Remington 1 1/2 primer with 2.6gr titegroup. Hodgdon calls for .980 inches for OAL. However, when I seat this bullet at that depth it appears the bullet is not in the case far enough to hold it securely. I measured the bullet and it is .427" long. Since this is a RNFP do I need to seat this further in like a hollow point? what is the length of a normal 100gr Round nose bullet? Mabe I can subtract the difference for better seating. Thanks

January 14, 2010, 08:57 PM	#3
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	0.123" deep is pretty shallow. Between .2 and .25 would be better. Try a COL of .870", and load 2.7 grains of Hodgdon Universal and work up toward 3.2 grains. Powder needs to come down a little when you seat deeper. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

January 14, 2010, 09:08 PM	#4
RidgwayCO Senior Member Join Date: March 22, 2008 Location: Western Colorado Posts: 244	Suggestion... load your .380 Auto bullets so that at least .175" or more of the bullet is seated in the case, to help ensure the case has a secure grip on the bullet. Then use this basic equation to figure your COL: .676" (case length) + .427" (bullet length) - .175" (seating depth) = .928" (COL) Now check to see if a dummy round loaded to this COL will function in your .380 Auto pistol. You can't really make it any longer (without adversely affecting the critical tension between the bullet and case), but you can make it shorter if necessary. Remember that if you decide to seat more of the bullet inside the case, then the COL will be less. Also remember that any rounds you make with a COL shorter than the data you're using will require you to reduce the amount of powder used. Pressure goes up quickly in those small semi-auto cases, especially when you're seating the bullet deeper than when the test data was shot. __________________ "A well regulated militia being necessary to the security of a free State, the right of the People to keep and bear arms shall not be infringed." Nope, not a single word about hunting...

January 15, 2010, 02:35 PM	#6
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	That's why the Universal loads I provided are smaller than Hodgdon's for same weight bullets at .980". I used QuickLOAD to make the adjustment. My copy of the Hornady second edition handbook, gives seating depth instead of COL. I think that is more useful information. As I've posted elsewhere, you can rearrange the formula to give COL from seating depth or to find seating depth from COL by swapping the two as the subtracted term. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

January 15, 2010, 05:22 PM	#7
RidgwayCO Senior Member Join Date: March 22, 2008 Location: Western Colorado Posts: 244	Yep Unclenick, you've gotta love QuickLOAD for working with varying COLs. It's not perfect, but it's a lot better than working in the dark... __________________ "A well regulated militia being necessary to the security of a free State, the right of the People to keep and bear arms shall not be infringed." Nope, not a single word about hunting...

January 14, 2010, 07:52 PM	#2
spacecoast Senior Member Join Date: October 14, 2009 Location: Sunshine and Keystone States Posts: 4,461	I have some 100 gr. Berry's plated RNHB (hollow base) bullets and they are 1.20 cm or about 0.472 inches. They would be slightly shorter than that (I believe) if they were RNFB.

January 16, 2010, 04:02 PM	#9
turbovr6 Junior Member Join Date: January 14, 2010 Posts: 3	Thanks, So the hornaday manual gives a seating depth for the 380 Auto? I think that would be more useful than OAL for a bullet that there is no load data for. I then can calculate the proper oal from the length of the bullet. Final internal volume is what is important to have correct. Not necessarily OAL. (Unless to properly feed). So what does Hornaday state for seating depth?

January 16, 2010, 04:05 PM	#10
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,061	Not any more. Only my ancient Hornady Handbook Vol 2. Copyright 1973. I don't know why they stopped the practice? No reason not to give both numbers if they wanted to. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

January 27, 2010, 05:02 PM	#11
turbovr6 Junior Member Join Date: January 14, 2010 Posts: 3	Thanks everybody. Worked out a nice recipe and found the OAL that really works. 100gr Extreme RNFP, Rem 1 1/2, Starline brass, 3.0gr Titegroup, OAL .935". Works beautifully in PPKS.

January 27, 2010, 08:06 PM	#12
RidgwayCO Senior Member Join Date: March 22, 2008 Location: Western Colorado Posts: 244	Congratulations! There's nothing better than finding a load that works great in your firearm. Any idea what velocity those loads are producing? __________________ "A well regulated militia being necessary to the security of a free State, the right of the People to keep and bear arms shall not be infringed." Nope, not a single word about hunting...

July 5, 2014, 09:17 AM	#13
Ryushin Junior Member Join Date: September 5, 2013 Posts: 2	Final Numbers I know I'm zombiefying an old thread, but Google brought me here. I duplicated this load and I wanted provide final numbers: Pistol Used: Sig P238 2.75" barrel Powder: Titegroup Bullet: X-Treme 100gr RNFP COL: 0.935 FPS looking for: just under 912 (95gr bullet, per Hodgdon) Temperature: 85 degrees Fahrenheit 2.80+-.02gr: 10 shot FPS: 832 821 829 818 819 829 820 841 834 847 Average: 829 FPS 3.00+-.02gr: 10 shot FPS: 896 874 906 887 893 900 914 900 870 896 Average: 894 FPS Wow. Perfect load. Very happy. Recoil is very mild. Wife really likes the new load. Functions perfectly through the P238.

July 5, 2014, 11:42 AM	#14
Clark Senior Member Join Date: December 4, 1999 Location: WA, the ever blue state Posts: 4,678	Different 380s will do different OAL. The longest I have is Husqvarna 1907 that will do 1.090" max. The shortest I have is a Kahr P380 0.965" max. __________________ The word 'forum" does not mean "not criticizing books." "Ad hominem fallacy" is not the same as point by point criticism of books. If you bought the book, and believe it all, it may FEEL like an ad hominem attack, but you might strive to accept other points of view may exist. Are we a nation of competing ideas, or a nation of forced conformity of thought?

July 5, 2014, 03:45 PM	#15
Ryushin Junior Member Join Date: September 5, 2013 Posts: 2	According to the reloading manuals, 0.984 is the max COL. The flat point bullet makes it harder finding a good COL. The post by RidgwayCO really helps in this. It would be nice if the reloading manuals and sites did mention what the max seating depth was. That is probably the most important piece of information instead of using COL.