I have come to th econclusion my 3000 win just has a slow barrel. I seem to be 100-150 fps slower than all books indicate should be. I had a load for 200 gr Accubonds that was very accurate. I was concerned where I would be for velocity so as a back I loades some 180 Accubonds and went for a velocity check. The max load of RL 22 in the 180's gave me in the high 2900's the a coiuple grains less than max on the 200's gave me only 2750. The funny thing was the 180 groups were bigger @ 100 than the 200 but they were smaller at 275. I think I am going to shoot the 180's I might try some H 1000 to see what happens there. What would you guys shoot? Mule deer in MT is the issue and maybe a cow elk here in CO. Thanks

Your chamber might be larger than normal,or your batch of powder may be a little slower than that used to provide the data that you are using.You may also be seating your bullets farther from the rifling.There is more than one possible explanation that could result in lower than posted velocity.

chain ----- I shoot two .358 STA's and one has always been 50-150 fps faster than the other with the same loads. Both are custom barrels, one from Winchester and the other from Lilja, the Lilja being the faster. I put it to the difference in chambers. The resized brass from the Winchester barrel will not chamber in the Lilja, the resized brass from the Lilja will chamber easily in the Winchester barrel. A thousandth here or there can make a difference. If my reasoning is wrong, someone with deeper knowledge enlighten me. Good shooting

Chambers, throats, finish of riflings; all can make a difference in the velocity yield with a given load. Without knowing what kind of pressure you are running, it is impossible to know whether your barrel is "slow" or not. For instance, a larger chamber will, all things being equal, yield lower velocities with the same load, but will also allow greater powder loads for the same pressure, thus allowing higher velocities at the same pressure.

It is possible that your gun may accept several more grains of powder than the listed "maximum" (a misnomer) and still stay within acceptable pressure limits. On the other hand, if you have a somewhat rough or tight bore, then you may find the your practical velocity limit is on the slower side for the cartridge.

I have both "fast" and "slow" barrels; however, until you establish the pressure limits for a particular gun, it is not possible to say much about the barrel's potential velocity yield.

By the way, for the most part (but not always), my "fast" barrel guns tend to be a bit more accurate. This leads me to believe that the difference is mostly in the bore finish. Others may have differing experiences.

quote:

Originally posted by chain: I seem to be 100-150 fps slower than all books indicate I should be.

Is your barrel the same length as the "book?"

I have a tikka t3 in 300 win mag. It shoots 180 accubonds at 2950 with 75 re22. With a 25" barrel I was hoping for a bit more. HOWEVER a little checking shows that I have a .250" jump from the case to the rifling with "clip length" ammo. I'm seriously wondering if this isn't almost acting like weatherby freebore. I see some data in older books that says max loads are 77 of RE22 and 78 I7828. I'm thinking that with my "sort of freebore" I should be able to go up to that level if I'm careful.
But...the bottom line is the 75 grains load is a tack driver and should I really need to squeaze that extra 100 fps just for my ego??

quote:

Originally posted by chain:
What would you guys shoot? Mule deer in MT is the issue and maybe a cow elk here in CO. Thanks

I would personally stay with the 180 grs AB. It will do fine for mule deer and cow elk. A friend of mine just took a bull elk in the rut with the .300 Win Mag/180 grs AB combination, worked a treat.

A high 2900s velocity is not slow for a 180 grs .300 Win Mag load - except on the Internet where all loads go 3200 and groups rarely come in above .5"...

- mike

You are right with those velocitiies. I was hoping to get to 2850 with the 200 and I guess I am close enough to 3000 on the 180 that was my goal. My barrel now is 24 inches I think they might be figuring those velocities from a 26" barrel. When I rebarrel I will go to at leasat 26" Thanks

I partial resize and I think that I have a bit of a jump from the bullet to the rifle. I think I measured the 200 Accubond hitting the lands with an OAL of about 3.67" I am guess mow I don't have the data infront me

quote:

I would personally stay with the 180 grs AB. It will do fine for mule deer and cow elk. A friend of mine just took a bull elk in the rut with the .300 Win Mag/180 grs AB combination, worked a treat.

A high 2900s velocity is not slow for a 180 grs .300 Win Mag load - except on the Internet where all loads go 3200 and groups rarely come in above .5"...

- mike

this goes for every rifle in this house hold at the moment, we have never had one copy the books velocity with the same ammount of powder, we are normally 100FPS behind and normally stick in another couple of grains in to catch up. i think books are very optimistic with velocity, and very cautious with powder ammounts. all except a single shot 308 we have, it doesnt like getting near the max listed loads.

quote:

Originally posted by kraky:
I have a tikka t3 in 300 win mag. It shoots 180 accubonds at 2950 with 75 re22. With a 25" barrel I was hoping for a bit more. HOWEVER a little checking shows that I have a .250" jump from the case to the rifling with "clip length" ammo. I'm seriously wondering if this isn't almost acting like weatherby freebore. I see some data in older books that says max loads are 77 of RE22 and 78 I7828. I'm thinking that with my "sort of freebore" I should be able to go up to that level if I'm careful.
But...the bottom line is the 75 grains load is a tack driver and should I really need to squeaze that extra 100 fps just for my ego??

i dont know about everyone else but, i go for accuracy first. 100FPS is neither here nor there and if you really want it try changing powders. i dont see the point of having a load doing 3200FPS with groups of 2 inches when you have a load thats doing 3000FPS and 3/4 inch

quote:

Originally posted by chain:
I have come to th econclusion my 3000 win just has a slow barrel. I seem to be 100-150 fps slower than all books indicate should be. ...

Hey Chain, Whatever you do, DO NOT get a negative inclination about your rifle. What you are seeing is more Reality than Abnormality.

Perhaps you have seen me mention(a few thousand times) that Chronographs can be misleading. I suppose I really should say they are normally always misleading - because they create the same angst you are experiencing in "everyone" that uses Velocity as a Goal.

I'm all for SAFE MAX Loads, but I could not care less about what the actual Velocity happens to be.
-----

The people that own the Haphazard Strain Gauge Systems are required to add a Fudge Factor in order to compensate for all the inadequacies of the devices. So..., in the same manner, I'd encourage everyone who uses a Chronograph to just add a Fudge Factor to what ever Velocity they read. If it make a person more happy to have the Bullet going 3400fps rather than 2900fps, just Fudge Factor in 500fps. Or pick what ever number you desire - because - it doesn't matter at all.

Don't let the Velocity cause concern about your rifle.

Best of luck to you.

quote:

Originally posted by chain:
My barrel now is 24 inches I think they might be figuring those velocities from a 26" barrel.

If it's 'now' 24" what did it used to measure?

Doesn't "the book" state test barrel length?

I guess you have a point . I just always thought that 26" was the norm for magnum facory barrels. I inserted now sub consciencely dreaming of the day I put a nice long custom barrel on this baby and shoot waaaay across the prairie.

My thoughts on velocity and maybe against all the forces of nature, I might, and I add just might be learning something. I am beginning to see that you don't get all that much more zing for the added powder you burn and the rotator cup damage you when you let go with one of the magnums.

Interested in learning something else?

Definition: The "rotator cuff" is the name for the tendons that surround the shoulder joint. The rotator cuff is actually a group of four muscles and their tendons that wraps around the front, back, and top of the shoulder joint.

quote:

Originally posted by Hot Core:
Hey Chain, Whatever you do, DO NOT get a negative inclination about your rifle. What you are seeing is more Reality than Abnormality.

I don't always agree with Hot Core.....usually however....but this statement is dead nuts on the mark!!!

quote:

Originally posted by vapodog:
I don't always agree with Hot Core...

Does anybody? I or he must be mellowing in our old age, as I never used to agree with what he had to say. Now I usually do. Go figure.

I had to look and see if the P was by the F on the keyboard. I guess I can't blame that mistake on my poor typing. I did mean on or about the shoulder.