Slow barrel 243, any suggestions??

[ReloadKy]

I have a Ruger American in 243 (22 inch barrel) that has proven to be very accurate with 95gr SST bullets and 65 gr V-Max bullets. I have been working on developing a 95 gr Nosler ballistic tip hunting load for this rifle. What I have noticed over the few years that I have owned this rifle and tested it, is that I never get even close to book speeds. Example: I have loaded a max load of Reloader 16 40.5 grains with the 95 gr NBT and my average velocity was 2820 fps. This is darn near 300 fps slower than Alliants data. I know that what powder manufacturers state and what reloaders actually get are rarely the same. However I keep very good records of loads that I create and chrono and I have noticed 200-300 fps difference with a variety of powders I have tried.
I know that shot placement is way more important than velocity but without initial velocity in a caliber like 243 there is a lot of energy left out of the equation. My son has a compact Rem 700 in 243 that has a 18 inch barrel and I get more velocity with the same load out of his rifle than I do mine, so I know it is not my loading process. Any idea what I should / could do with this rifle to try and get the velocity that I should be getting?

 

[sako2]

Try seating your bullets longer. My 6.5 prc load lost speed . I seated the bullets longer and got the speed back. Do you have a lot of carbon on the outside of the neck?

 

[ElmerThud]

You have to remember published data is from testing under laboratory conditions. When you chrono, you're effectively 'Field testing' the results are never going to be the same as those produced under lab conditions. Also, the lab barrel is definitely not your barrel.
My .243 Steyr Mannlicher stutzen 20" barrel using the Nosler 95gn BT with Vihtavouri N160 (43gns = Rem. LR Primer) produces around 2920fps MV & is very accurate. It's an old rifle now from 1990 but still great.

 

[bdbrown66]

Brad, I usually don't worry too much about what the load data says I should get. I've found that usually that data is from a barrel that is several inches longer than my hunting rifle's barrel, so it's not an apples to apples comparison. But to your point, here's a load I've used successfully in the past. It's right up at the top of the load data, and IIRC that's what it took to get the results I wanted.

 

[Ridge_Runner]

it takes pressure to make velocity. bump the charge up till you see pressure signs then back off aa bit. books are just a guideline.

 

[TackDriver284]

I had the same issue in a few rifles like the 6.5 x 284, 7mm Mag and 300 Magnum. I was seeing slow speeds which was about 200 to 300 fps slower than book max speed even if I used their max powder charge. I had 2 options, either retest under a chrono, in .3 - 4 grain increments in 3 round groups or do a ladder test first until you start seeing pressure and back off maybe a half grain or a grain once you hit pressure. On a couple of rifles I was 3 to 4 grains over book max and got the speeds I wanted without pressure signs. I always check for ejector marks, I even take a magnifying glass with me to the range. Once I see ejector marks, I stop shooting and pull the remaining unfired bullets. I don't always follow the exact book loads, barrels are different, bullet bearing surface, distance to lands, and powder burn rates are some of the reasons for lower or higher velocities.

 

[RL338]

My son has a compact Rem 700 in 243 that has a 18 inch barrel and I get more velocity with the same load out of his rifle than I do mine, so I know it is not my loading process.

What is the velocity difference between the same load with both rifles?

Example: I have loaded a max load of Reloader 16 40.5 grains with the 95 gr NBT and my average velocity was 2820 fps.

Is this max load with pressure signs in your rifle or just based off of a book max?
If you’re seeing pressure with this low velocity , a good barrel cleaning may be in order. Not knowing the barrel round count , I’d be looking for a carbon ring.

 

[slickrem]

you want more velocity ? settle for the 85 grain bonded bullet if you want to achieve what the 95 grain will do...next...Ackley Improved, which I never cared for myself, kind of like the pointless debate over .243 Winchester verses the 6mm Remington's extra velocity, marginal. Lastly, rebarrel with a faster twist longer barrel, but then you loose lighter bullets.

 

[Blkram]

Is your barrel rough...or just a slow barrel that may take time to "season" so to speak and will eventually start to produce better velocities?
Some rifles require a few hundred rounds before they start to produce...
DrMike experienced this with one of his rifles and I am sure that he will be along and can elaborate further...IIRC his rifle took more than 400 rounds to start to improve.
Otherwise, as you have already noted, and others have already commented on...each barrel produces different results for a variety of reasons and there is rarely a true apples-to-apples comparison in velocity, even from identical barrels made from the same batch, chambered and threaded with the same reamers, one right after the other.

 

[DrMike]

Is your barrel rough...or just a slow barrel that may take time to "season" so to speak and will eventually start to produce better velocities?
Some rifles require a few hundred rounds before they start to produce...
DrMike experienced this with one of his rifles and I am sure that he will be along and can elaborate further...IIRC his rifle took more than 400 rounds to start to improve.
Otherwise, as you have already noted, and others have already commented on...each barrel produces different results for a variety of reasons and there is rarely a true apples-to-apples comparison in velocity, even from identical barrels made from the same batch, chambered and threaded with the same reamers, one right after the other.

It was a Winchester 280 that required well over 400 rounds before it settled down. I really wanted the rifle or it would have gone down the road early on. Now, it is a consistent sub-MOA shooter that has accounted for a goodly number of deer.

 

[AFG270]

Try switching powder.
I have the same rifle, Ruger American 243 Win. When I started reloading for it there were no Ballistic tips available, so I bought 100g btsp Interlocks and 95g SST. I started with StaBall 6.5 and the 100g btsp and had the same issue as you, Hodgdon's max of 42.0g=3085 fps with 24" barrel, I got 2855 fps with a 22" barrel. I worked up to 43.2g with no pressure signs and only got 2930.

Switched to RL26, Alliant max with a 100g Sierra sp 47.9g=3202 fps with a 24" barrel, I worked up to 48.0g=3152 fps. More like it.

The 95g SST I went with RL26, worked to 49.0g with no pressure signs and 3254 fps, backed off to 48.3g at an average velocity of 3178 fps and sub moa group.

Also shooting 80g Hammer Hunters over StaBall at 3302 fps average and a standard deviation of 1 and sub moa.

I also hand lapped the barrel as it was very rough and that made cleaning much easier.

 

[ReloadKy]

I appreciate all of the suggestions. Several of the suggestions I have already tried. Not real sure what my next steps with this rifle will be. I have never experienced any pressure signs so I may just need to carefully creep up the powder to try and get the velocity (end result kinetic energy) that I want.

 

[KinleyWater]

I appreciate all of the suggestions. Several of the suggestions I have already tried. Not real sure what my next steps with this rifle will be. I have never experienced any pressure signs so I may just need to carefully creep up the powder to try and get the velocity (end result kinetic energy) that I want.

Sorry I have nothing to add, but I think this post is yet another example of why I really like this forum - sharing, learning, curiosity, and humility.

Thanks for being a part of the forum.

 

[SJB358]

So here is one of the many many times that book data for a certain powder and bullet hasn't nearly lined up. I don't totally believe in fast or slow barrels, cause pressure equals speed in most cases unless you just have a really restrictive bore, and some bores are a hair larger than norm and take more powder than prescribed to get there. Just my theory from monkeying with this stuff a little bit. Case capacity means something too, along with the throats.

But anyhow, my BIL's P64 270 Win Fwt. Noslers data was 59 grains max with a 24" barrel netting about 3100, give or take.





This was the data we were working off of with the 130 AB's. We ended up at 60 grains of H4831 for 2989 average for 3 rounds over the Magnetospeed. Having worked with a pile of 270's, I knew the lower charges were likely to be way shallow in FPS. I did take into account the 22" barrel but even still it was dog slow. Accuracy at the lower charge weights was pretty poor as well. As we started creeping up some groups came together, and I stopped at 60 grains since accuracy was very good.







So we were at least a grain over Nosler's max, but on par or under a couple grains from other sources, but without a chrono we might have given up on H4831 pretty quick assuming the powder didn't shoot. I would also guess we could have increased the charge another grain or two and still been in a safe place, but once accuracy is good enough, I tend to leave it alone as long as it is consistent.

I have had this happen numerous times and don't encourage anyone to surpass book data, unless they have a chronograph and some decent understanding of what is going on. Not just Nosler either, it happens across the board. Throats, case size, bores, etc all play their part in what I think people call a slow or fast barrel.

A long throat with a slightly oversize bore is going to take more powder than a shorter throat and a slightly tighter bore but until you know the speed and where you're at.

Powder variation is another. I have had fast lots of H1000 that were the same as my Retumbo. But as all the manuals say, you do this at your own risk, but with a bit of caution you can usually get where you want to be.

I will typically load from highest to lowest in 06 or magnum sized cases in .5 grain increments, with 1 round a piece just get an idea of where I am at speed wise. If I am way below where a given bullet/cartridge is capable of, I'll keep inching up till I get to a speed that I'd be happy to hunt with.

Just my 2 cents..

 

[DrMike]

Excellent explanation and workup, Scotty.

 

[ReloadKy]

Thanks a lot gentlemen.