Does higher velocity give better groupings?

[jedi]

Testing the following in my .30 carbine (auto-ordnance paratrooper replica)

WIN 296 @ 14gr with 110gr FMJ
vs
WIN 296 @ 14.5gr with 110gr FMJ

On the 25 yard range when shooting from bench rest:

At 14gr the rounds are 3" too high and the groupings of 3 shoots are about 1" apart.

At 14grs the rounds ate 1.5-2.5" to high and the grouping of 3 shoots are 1/4 to 1/2 apart.

On the shooting high issue I know what I need to do. (Ie. raise the front sight by .06 of an inch) but is the high velocity giving better groupings? Is that something I should expect. Max for this powder is 15gr and at 14.5 it feels a lot different than 14g Not comfortable going over 14.5 with this powder as it's already snappy not a lot but some.

Also I see more smoke when shooting at the 14 then the 14.5. Actually I don't see any smoke at the 14.5 level. Hum wonder if I should try 14.75 but again not real sure I want to.

Thanks

 

[bstewrat3]

Every gun will have it's preference on where it shoots best velocitywise, but with W296 it will usually perform best toward the top loadings because of the way it needs pressure to burn it's best.

 

[hammer24]

Generally speaking when I have done load work ups with H110 (w296) I've gotten my best groups as I've approached the max suggested load. I've not loaded the .30 carbine yet, but I run other calibers with the powder and pretty much load to max because my guns like it best.
If that is a product of velocity alone, I don't know. I suspect more is happening to shrink the groups than only velocity (burn consistency, pressure consistency, etc.)

 

[jblomenberg16]

Most, but not all of my rifles seem to do best very close to the max load.

 

[baldguy637]

It's all in what your guns like, powder, primers, bullets all come into play.

Personally I've only found one max load that shoots the best in one of my guns, and it happens to be a .357 load with W296 and a 170gr soft point. Im more of an accuracy shooter, I'd rather shoot slower loads that I can stack together rather than a hot load that opens up. That's the fun of reloading, you get to find what works best for you and your guns.

Good luck

 

[jedi]

well then looks like i have some more work to do then in terma of reloading.

 

[warthog]

Most every rifle cartridge will yield higher accuracy as the case is more completely filled up, to include compressing a load. The .30 Carbine isn't really a rifle round though, more like a super duper pistol round, so I am not sure if it performs in the same way. These types of loads are usually up in the max range and need to be worked up to of course but a general rule is the more full the case, the better the accuracy. You can read more about why this is in the new Berger Bullet manual plus I have seen a lot of it on their website as well. I learned more about accuracy than I had ever known before reading that manual and then using what I learned in my handloads for accurate rifle shooting at long range. YEMV however.

 

[Broom_jm]

well then looks like i have some more work to do then in terma of reloading.

Why do you say that?

Your 14.5gr loads sound about perfect, to me. They are sealing properly to the chamber walls (less smoke), they are giving better accuracy, and they are exiting the barrel sooner, hence the lower POI at 25 yards.

H110 powder was created for the 110gr bullet you're firing from the 30 Carbine. The 14.5 grain load is pretty dang close to ideal, delivering consistent cycling of the action, good accuracy and suitable terminal performance, should it ever come to that.

Why would you think you need to change anything?

 

[shibumiseeker]

Accuracy is dependent on several factors, each of which is affected by numerous variables.

Accuracy potential of the barrel

A barrel itself will have nodes in the resonance of the barrel (how it vibrates in response to the pressure wave) where the end of the barrel is neutral in relationship to the chamber, this gives the best accuracy with ALL other variables accounted for. These nodes are unique to each barrel and there's generally 2-3 of them for any given round velocity range. Often times these nodes are not near the max velocity.

The rifling of the barrel, and the crown of the barrel also affect the bullet but affecting how evenly the bullet is engaged when it enters, and how it is destabilized as it exits.

The bullet itself:

Bullets have a velocity range at which they are the most accurate. This is dependent on the design and style of the bullet. Some designs are very sensitive to velocity and have a very narrow range which may or may not be near the max for a given round. How close the bullet is before it engages the rifling has an affect.

The powder charge/priming:

In general the optimal situation is to have the powder burn very consistently giving the closest velocities. This can affect the barrel vibration, it can affect how the bullet engages the rifling, and it can affect how much the bullet drops at distance.

The brass itself:

Brass can have volume differences which affects how the powder burns, the priming flash hole, as well as the primer itself can also change that. The tension on the neck and how it holds the bullet, and how concentric the neck is all come into play.

Environmental:

Things like the temperature, humidity, and altitude, all have affects on all of the above.



ALL of these factors and their variables interact with each other and as in chaos theory, there are areas of stability where large changes can be made in some variables with no affect, and other areas where the smallest changes can have enormous consequences. As an example: if the bullet is in its stable range and the barrel is at one of the nodes in its vibration, relatively large changes in velocity (several percent) can still be very accurate even at distance. This can be demonstrated by the ladder test where differences in powder charge as large as several tenths of a grain have no effect at all. Once you get outside of that range within that node though, the combination becomes very sensitive to even the smallest changes.

 

[jedi]

Why do you say that?

Your 14.5gr loads sound about perfect, to me. They are sealing properly to the chamber walls (less smoke), they are giving better accuracy, and they are exiting the barrel sooner, hence the lower POI at 25 yards.

H110 powder was created for the 110gr bullet you're firing from the 30 Carbine. The 14.5 grain load is pretty dang close to ideal, delivering consistent cycling of the action, good accuracy and suitable terminal performance, should it ever come to that.

Why would you think you need to change anything?

Before reading yours and shibumiseeker post I though higher velocity = better accuracy. So if 14.5gr was good, then 14.75 would be better so long as I stayed under the 15gr which is MAX.

The reason I originally did 14 and 14.5 was because I only had access to berry plated bullets and the velocity of 14.5 is very close to the max of those bullets. My original 25 reloads were 14 - 14.5 with Berry's. Since then I was able to get FMJ so the issue with the plated bullets separating in the barrel is no more and thus I feel comfortable going higher than 14.5 with those bullets.

So figured 14.6, 14.7, 14.8 not sure I want to do 14.9 or 15. 14.5 is already somewhat snappy and figure the others are only gonna get worse.

Thank you for helping me understand the reason for the less smoke.
Well it's off the clean the .30 carbine today and starting the whole process over again. **SIGH** I hate trimming I hope it's not a lot this time.

--SIDE NOTE--
Based on yesterday's data and this article:
Formula For Changing Height of Front Sight

I looks like I need to raise the front sight by .06" = 1.52mm. That is a very tiny amount and I'm not sure the JB Weld route is going to be worth it. Seems like I'll be adding a tiny, tiny, tiny amount to the front sight.

 

[Broom_jm]

If this was a bolt-action rifle, with a high-power scope, shooting at extended ranges, maybe your load development would still need some tweaking. For a semi-auto 30 Carbine, you want function (check), reasonable accuracy (check) and a safe, effective pressure range (check).

If you want to keep trying heavier charges to get even better results, I can't say as I blame ya, but from a purely practical standpoint...yer good! Many folks use 14.5 grains as their go-to load, with 110gr jacketed bullets. You're already getting nearly ideal results from that load, don'tchya think? What more would you be looking for, with the tenth of a grain increases?

 

[warthog]

While I can't say I work too hard to make semi-auto ammo all it can be, I can't see discouraging you if this is your goal. In fact I think it is an interesting experiment and one worth following. I shoot .30 Carbine often myself though I tend to look for it to cycle the gun well, be as clean burning as it can be, and reasonably accurate. I pretty much load 110gr cast boolits since that is what I cast for myself. I also load jacketed bullets of the same weight and once I get them working well, I let them be.

I also have a Blackhawk in .30 Carbine. I haven't done much work to see how accurate I can gert with it. Maybe I should this summer.

 

[jedi]

If this was a bolt-action rifle, with a high-power scope, shooting at extended ranges, maybe your load development would still need some tweaking. For a semi-auto 30 Carbine, you want function (check), reasonable accuracy (check) and a safe, effective pressure range (check).

If you want to keep trying heavier charges to get even better results, I can't say as I blame ya, but from a purely practical standpoint...yer good! Many folks use 14.5 grains as their go-to load, with 110gr jacketed bullets. You're already getting nearly ideal results from that load, don'tchya think? What more would you be looking for, with the tenth of a grain increases?

Well one part of me just wants to plink with the rifle and it saying heck 14.5gr is giving you OK results as you stated above so just start mass production at that rate and be done with it. I will either have to learn to adjust to the shooting a bit high. Granted I know this rifle is more for the 150 yard range and it's not a "sniper rifle" or even "front line battle rifle" as it was designed for support units and on the go units so yes you are correct why bother to try and frustrate myself.

The other 1/2 of me is wait... wait... you know you want to mess with the numbers some more. I'm so going to be in trouble next year when I move up to .308.

 

[actaeon277]

Ok, I'll start off with the admission that I'm not familiar with your 30.

But I do know that pushing the fps too high can be detrimental on certain rifles with a high twist rate in the barrel.

You have now exhausted my knowledge.

 

[jedi]

Well I could not resist reloading hobby!
I went ahead and reloaded the following:
WIN 296

14.1 gr w/ 110gr Platted Bullet x 6
14.1 gr w/ 110gr FMJ x 6
14.2 gr w/ 110gr Platted Bullet x 6
14.2 gr w/ 110gr FMJ x 6
14.3 gr w/ 110gr Platted Bullet x 6
14.3 gr w/ 110gr FMJ x 6
14.4 gr w/ 110gr Platted Bullet x 6
14.4 gr w/ 110gr FMJ x 6
14.6 gr w/ 110gr FMJ x 13
14.7 gr w/ 110gr FMJ x 13
14.8 gr w/ 110gr FMJ x 13
14.9 gr w/ 110gr FMJ x 13

I skipped 14.0 and 14.5 since I still have some of those both with plated and FMJ. So the next time out at the range I'll see how all these group on the 100 yard and whatever works best I'll stay with that.

Did make one slight mistake when I was loading the 14.6gr ones. I initaly did it both with FMJ and platted bullets. After I was done with the 14.6gr I realized the error of using platted bullets. I'm not sure what the velocity is at 14.6 but Berry's Platted Bullets suggested not to load more than middle of the road with their bullets. Middle of the road is 14.5 so I rather not tempt faith.

I'll post again when I get the results.

 

[avcautoinc]

i would think if you can see a difference at 25 yards then you have your answer

 

[Broom_jm]

Sometimes, inquiring minds just gotta know!

 

[jedi]

Sometimes, inquiring minds just gotta know!

Oh I blame you & only you!
Cause you said 14.5 is good enough why bother to test anymore and that just made me go hum.... NOW I GOTS TO KNOW!!!
:faceplam:

& what gets me is I know this is not a super accurate rifle (it was not designed for that) so why bother spending so much time to make it something it is not.

But it's a good experience in patients and understanding more on reloading before I finally move to .308 next year.

 

[Broom_jm]

Oh I blame you & only you!
Cause you said 14.5 is good enough why bother to test anymore and that just made me go hum.... NOW I GOTS TO KNOW!!!
:faceplam:

& what gets me is I know this is not a super accurate rifle (it was not designed for that) so why bother spending so much time to make it something it is not.

But it's a good experience in patients and understanding more on reloading before I finally move to .308 next year.

My work here is done, folks!

And when you DO start making those 308 loads, your approach is going to be superb! Maybe not in one tenth increments, but three tenths is perfectly reasonable for really narrowing it down to the most accurate load possible.

 

[jedi]

My work here is done, folks!

And when you DO start making those 308 loads, your approach is going to be superb! Maybe not in one tenth increments, but three tenths is perfectly reasonable for really narrowing it down to the most accurate load possible.

three tenths!!!! Looks like I might need to get another scale then.
I've been using the Hornady GS-1500 Electronic Powder Scale 1500 Grain Capacity but it's not capable of 3/10th.

I do also have an RCBS 5-0-5 scale that I got ebay but have never been able to get it to zero. The prior owner had the same issue with it. One of these days I might call RCBS to see if they can help me out.