OAL and accuracy

[Red Ryder]

Folks correct me if I am wrong, but I thought the longer the OAL ( as long as the gun eats it) the better the accuracy? But I do not see many people loading out to 1.150 or 1.160 in their "pet loads". I do see so many people using a shorter OAL ( <1.130 ). Aren't these rounds less accurate?

I am loading MG 124 and 147 CMJs with TG, Federal SP primers,and a .376 crimp and shooting a 4.5 inch XDM. I want a PF of 135. I am looking to all the experienced folks to give up a TG recipe to keep me from farting around for a month or a year looking for accuracy and 135 PF! I wanna be a shooter....not a reloader!

[gm iprod]

My opinion and experience: Relibility, it can be as accurate as a bench gun and be worthless if the next rounds stays in the magazine. The accuracy potential of most handguns and it's attached simian is not good enough to warrant making the gun drill them all through the same hole at 500y. Most handguns run much dirtier than rifles (especially if using lead) and a small gap at the front to allow the next round into a filthy chamber would be useful.

My own personal NRA Action Pistol shoots better at 1.225" (38Super not 9mm) but similar theory. My Glock works better at 1.125 with a 125gr JHP, but with the same brand same weight FMJ it is best at 1.150". Which is essentially the same seating die setting.

MAny match guns have a tight chamber and sometimes just make the load shorter seems to work. I used to get all my loads right out to the maximum it will chamber, just did not seem to work as accurately or reliably. Mor eimportantly with my swinging on the other end I just could not see the advantage of making the gun less reliable for a miniscule gain in accuracy..

[CeeZer]

What IPROD said - it's always a compromise between accuracy, reliable chambering and reliable feeding, in short.

[Hi-Power Jack]

Folks correct me if I am wrong, but I thought the longer the OAL ( as long as the gun eats it) the better the accuracy?

My Browning Hi-Power is more accurate at 1.12" OAL with 147 gr MG

jhp and W231, but it doesn't feed consistently until I get it out

to 1.13".

That loses a little accuracy, but feeds much better.

Jack

[Corey]

not all guns will shoot the same. in fact no 2 guns will shoot the same. you have to find out the best system for your particular gun. In this game, its reliability over accuracy that rules. we can afford a 3" group at 25 yards instead of a 1" group, but we cant afford to have a jam on every magazine.

Now if your shooting long distance rifle or a benchrest competition, thats a whole 'nother story.

[kv501]

I have an XD which sees mostly plinking and an M&P9 L that I shoot production with. Both of them get the same load.

I load 124 gr MG JHP over 4.2 grains of TiteGroup, 1.125 with Federal primers and in both guns that load is quite a bit more accurate thatn a longer OAL. It also makes almost identical power factors @ 137 (that is as low as I am willing to go) out of both guns.

It is not so much a function of a certain OAL being inherently "accurate;" it is a matter of what is accurate in your gun. I have several loads in several calibers (pistol and rifle) which are deadly in the gun I shoot them out of, but won't group at all when fired in other guns. What I would suggest is:

1. If your gun is sensitive to OAL find a length which will feed reliably, 100% all of the time, no questions asked. In this game you have nothing without reliability. You can be the best shot in the world but if you start tanking stages because your stuff won't run this sport is going to be zero fun.

2. Once you have that established, try different charges until you find the most accurate load (obviously make sure it ejects EVERY time too.

Don't take power factor into account until you have done those things. If I have a load that is at 140 power factor, feeds 100%, but only groups 3 inches at 25 vs. a load that shoots 130 PF, won't feed all the time, but groups a half inch at 25, I'm talking the first one for sure.

Bottom line is try to get all the preconceived notions (like a longer OAL being more accurate) out of the way before you start. Find one that runs, then narrow it down to the most accurate one that does. My highly amateur opinion is that you are going to gain a whole lot more if your time is spent shooting rather than chasing OAL's and charge weights around .

[CZinSC]

For OAL, use the info you see as a guide, not Gospel. You need to test various OALs in your gun to see what accuracy you get. I just did this last week with SP01. I loaded up 20 rounds each of VV N320 at various OALs (same powder charge, 4.3gn ): 1.130 through 1.165 in .005 increments. ( it helps to have the Redding Comp Seating die to make this process easier ).

I then tested all at 15 yards, using a rest. I found that 1.155 was best, with 1.160 and 1.165 a close second. So you need to work up the load to your gun.

[JAFO]

I'm in the process of finding my best OAL for a new load now. I'm getting 135PF with Zero 124gr FMJ and 4.4gr of Titegroup loaded to ~1.16" out of my 226, but the accuracy is horrible. Groups are >6" from a sandbag at 15 yds. I'm hoping varying the OAL will allow me to find a sweet spot. It's either that or start trying different bullets.

[blind bat]

I need to run < 1.090" with 144gr MG JHPs in my CZ otherwise the gun won't go into battery! The camber is that short. My glock mags stick if I load longer than 1.155" with a 147gr CMJ so I load those to 1.145"

[gordonm1]

I'm in the process of finding my best OAL for a new load now. I'm getting 135PF with Zero 124gr FMJ and 4.4gr of Titegroup loaded to ~1.16" out of my 226, but the accuracy is horrible. Groups are >6" from a sandbag at 15 yds. I'm hoping varying the OAL will allow me to find a sweet spot. It's either that or start trying different bullets.

I'm loading for my 226 with 124gr MG hp. 4.3 gr tightgroup at 1.16 was alot more accurate than 4.4g. I had a jam over 200 rounds testing this weekend so I increased my crimp a little. My crimp was leaving a ridge at the case to bullet junction.

You might want to try load workup again much shorter with the zero's. If you have another 9mm, my suggestion is try 4-4.3 grains again with a length that will work with both guns. I may be going this route if the increased crimp does not get me to 100% reliability.

[CZinSC]

I'm in the process of finding my best OAL for a new load now. I'm getting 135PF with Zero 124gr FMJ and 4.4gr of Titegroup loaded to ~1.16" out of my 226, but the accuracy is horrible. Groups are >6" from a sandbag at 15 yds. I'm hoping varying the OAL will allow me to find a sweet spot. It's either that or start trying different bullets.

Shooting out of a CZ SP01, at 15 yards, I was getting approx 3" groups(or less) with 4.3gn TG with Zero 124FMJ (box will say 124 but they are actually 125). I was using 1.150 OAL and was averaging 133PF.

Point is, weigh your bullets, verify if they are 124 or 125. And second, I would come down on load to 4.3, and try 1.150 or 1.145, and see what that does to your accuracy. You may even go as short as 1.140. I got good accuracy at those lengths too.

I'm not loading VV N320 and it's opposite. Longer is better, my accuracy is best at 1.155.

[JAFO]

I've weighed bullets from my current box and they are closer to 125gr.

I was planning to lessen the crimp to see if that's the problem, but reading about problems with too little crimp has me wanting to keep it as is for now. I've run thousands of rounds at my current crimp die setting with no feeding issues. (Oops. Did I just jinx myself? )

[CeeZer]

I'm in the process of finding my best OAL for a new load now. I'm getting 135PF with Zero 124gr FMJ and 4.4gr of Titegroup loaded to ~1.16" out of my 226, but the accuracy is horrible. Groups are >6" from a sandbag at 15 yds. I'm hoping varying the OAL will allow me to find a sweet spot. It's either that or start trying different bullets.

Shooting out of a CZ SP01, at 15 yards, I was getting approx 3" groups(or less) with 4.3gn TG with Zero 124FMJ (box will say 124 but they are actually 125). I was using 1.150 OAL and was averaging 133PF.

Point is, weigh your bullets, verify if they are 124 or 125. And second, I would come down on load to 4.3, and try 1.150 or 1.145, and see what that does to your accuracy. You may even go as short as 1.140. I got good accuracy at those lengths too.

I'm not loading VV N320 and it's opposite. Longer is better, my accuracy is best at 1.155.

3" groups at 15 yards are too much spread, you need to learn the grip, stance, aiming and such...

OAL and powder charge are dependent on the particular gun and personal preferences. Some bullets will require shorter OAL and thus dictate lower powder charge too.

Edited February 4, 2011 by CeeZer

[rhyrlik]

OAL affects accuracy by fine tuning the load to your gun. There is no hard set rule. I usually start long and work my way down.

[MrP]

I'm in the process of finding my best OAL for a new load now. I'm getting 135PF with Zero 124gr FMJ and 4.4gr of Titegroup loaded to ~1.16" out of my 226, but the accuracy is horrible. Groups are >6" from a sandbag at 15 yds. I'm hoping varying the OAL will allow me to find a sweet spot. It's either that or start trying different bullets.

I'm loading for my 226 with 124gr MG hp. 4.3 gr tightgroup at 1.16 was alot more accurate than 4.4g. I had a jam over 200 rounds testing this weekend so I increased my crimp a little. My crimp was leaving a ridge at the case to bullet junction.

You might want to try load workup again much shorter with the zero's. If you have another 9mm, my suggestion is try 4-4.3 grains again with a length that will work with both guns. I may be going this route if the increased crimp does not get me to 100% reliability.

I've found an OAL of 1.148 produces the best results out of my 226. 3.8gr Bullseye with Tula Small Pistol Magnum primers and a 124gr MG JHP produced 3 5 shot groups of 1 9/16" or less last night at 25yds benched. The components aren't ideal but they're what I have lying around, and have proved to be fairly accurate and 100% reliable.

Edited February 5, 2011 by MrP

[JAFO]

I've found an OAL of 1.48 produces the best results out of my 226. 3.8gr Bullseye with Tula Small Pistol Magnum primers and a 124gr MG JHP produced 3 5 shot groups of 1 9/16" or less last night at 25yds benched. The components aren't ideal but they're what I have lying around, and have proved to be fairly accurate and 100% reliable.

Can I assume you meant 1.148"? An inch and a half is a little long.

What PF do you get with 3.8gr at that OAL? 3.9gr gave me 124 PF at 1.16", so I'm curious what kind of velocity increase I might see as I shorten the OAL.

Edited February 5, 2011 by JAFO

[CZinSC]

I'm in the process of finding my best OAL for a new load now. I'm getting 135PF with Zero 124gr FMJ and 4.4gr of Titegroup loaded to ~1.16" out of my 226, but the accuracy is horrible. Groups are >6" from a sandbag at 15 yds. I'm hoping varying the OAL will allow me to find a sweet spot. It's either that or start trying different bullets.

Shooting out of a CZ SP01, at 15 yards, I was getting approx 3" groups(or less) with 4.3gn TG with Zero 124FMJ (box will say 124 but they are actually 125). I was using 1.150 OAL and was averaging 133PF.

Point is, weigh your bullets, verify if they are 124 or 125. And second, I would come down on load to 4.3, and try 1.150 or 1.145, and see what that does to your accuracy. You may even go as short as 1.140. I got good accuracy at those lengths too.

I'm not loading VV N320 and it's opposite. Longer is better, my accuracy is best at 1.155.

3" groups at 15 yards are too much spread, you need to learn the grip, stance, aiming and such...

OAL and powder charge are dependent on the particular gun and personal preferences. Some bullets will require shorter OAL and thus dictate lower powder charge too.

Perhaps my terminology is inaccurate. When I say 3" group, I mean all the bullets are hitting within a 3" diameter circle. Is that not a 3" group, or would that be 1.5" group?

[JAFO]

Perhaps my terminology is inaccurate. When I say 3" group, I mean all the bullets are hitting within a 3" diameter circle. Is that not a 3" group, or would that be 1.5" group?

What you are describing is a 3" group. I think what CeeZer means by too much spread is that a 3" group at 15 yds will expand to a 6" group at 30 yds. Since the "A" zone of a metric target is ~5.9" wide, a group size of 6" starts giving you a chance of missing the A zone at 30 yards when your aim is dead on. This might not be much of a factor on close-in targets, but on a classifier with shots at 30 or 40 yards, or 6" plates at 30 yards, you could have C's or misses instead of A's or KDs.

Edited February 6, 2011 by JAFO

[MrP]

I've found an OAL of 1.48 produces the best results out of my 226. 3.8gr Bullseye with Tula Small Pistol Magnum primers and a 124gr MG JHP produced 3 5 shot groups of 1 9/16" or less last night at 25yds benched. The components aren't ideal but they're what I have lying around, and have proved to be fairly accurate and 100% reliable.

Can I assume you meant 1.148"? An inch and a half is a little long.

What PF do you get with 3.8gr at that OAL? 3.9gr gave me 124 PF at 1.16", so I'm curious what kind of velocity increase I might see as I shorten the OAL.

Yes, thank you for the heads-up. 1.148 is what I meant and it makes a PF of just above 128. This isn't my competition load, just a new favorite for plinking.