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223 barrel length?

I have a project gun chambered in 223.
It has the f-class 7.97 5c Broughton barrel in 30 inch length.
I am not getting the velocities I was hoping to achieve with the longer barrel and bullet weight / powder combo.
I am using Varget working up loads from 22.5 grains up to 24 grains behind 80 grain berger vlds I am only getting 2757 fps avg with the 24 grains and the programs say it should be over 2900 fps.
I am going to try IMR 4895, it is suppose to give me 2955 fps.

My question is could the barrel length be actually slowing down the velocities.

Any bolt gun shooters out there shoot this long a barrel?
thanks
 
I do not think your barrel is the problem.
When you say the program, do you mean Quickload? Is it data from Berger generated with Quickload?
If so, I suspect that the data was run with the bullet well into the case for a 2.26 COL. I noticed with Berger data for the 75VLD that 24 of Varget was much slower than it was listed as. They were loaded to the rifling as Berger said to do. The listed vel was 2870 in a 24" barrel and I got 2747 in a 26". As far as Varget powder is concerned, Hodgdon's data for the 80SMK lists a top velocity of 2869fps in a 24" barrel. I got 2864 in a 26" using their load,except COL wasn't exactly the same). The difference I suspect, is that they tested at a COL of 2.55 which is more in line with loading long range bullets that are fired single-shot. Berger did not indicate on their sheet what COL or components were used, so I just suspect that their data was generated with a smaller 'boiler room' than really exists when loaded out to the lands.
What COL are you using Steve?
 
With a .223 26-28 is max for the powder burn duration with that case capacity. I tend to think 26 is better. With 80 grain bullets an a 7.5-8. twist barrel you will be lucky to get an accurate load running over 2850. With the 75 grain Berger in a 8 twist Broughton 5C I am getting 2950-3000 fps with VV540. The brass takes a beating and is replaced about ever third shot. They are still supersoinic at 1000 yards. I would never shoot this in a gass gun.

Rustystud
 
I was refered to quickload program. My seated OAL is 2.510 with 80 grain berger and that just touches the lands. This puts the where the boatail section starts at the neck shoulder junction so part of the boatail does extend into the case. 1 and 8 twist was recommended by Tim at Broughton and length too, and we discussed that if I was loosing velocity that shortening it was be the option.
I increased my loads all the way up to 25.5, but ran out of room because that was a slightly compressed load.
24.5 grain of Varget shot an average of 2803 fps with the sd's and es's in the low teens, 100 yard group measured outside edges of the one hole for 4 shots,rounds 2 through 5) was .304, minus the .224 gives me .08 inch group, however the first round went about 1/4 inch below as it was a fouling cold bore shot. But a half a grain on each side and the groups was 1/2 inch, it also shot a 1 hole group at 23 grains that was .412 outside edges but velocity was way low. 25 grains ran 2880 and 25.5 grains ran 2955 fps but the group was terrible, almost an inch.
As far as pressure was concerned I saw no visible pressure indications except on the 25.5 grain load I started seeing the primer flattened out pretty good, but from 25 grains down to 23 the primers looked identical, but this was using Lapua brass.
Varget does seem dirtier though, I am going to try the IMR and possible some others in the future but it sure shot that 24.5 grain of varget really good, I'll have to see how it does at longer ranges when time permits.
 
Steve said:
I have a project gun chambered in 223.
It has the f-class 7.97 5c Broughton barrel in 30 inch length.
I am not getting the velocities I was hoping to achieve with the longer barrel and bullet weight / powder combo.
I am using Varget working up loads from 22.5 grains up to 24 grains behind 80 grain berger vlds I am only getting 2757 fps avg with the 24 grains and the programs say it should be over 2900 fps.
I am going to try IMR 4895, it is suppose to give me 2955 fps.

My question is could the barrel length be actually slowing down the velocities.

Any bolt gun shooters out there shoot this long a barrel?
thanks

Bet if you cut 7 inches off your barrel the vel's would go up.....
 
Steve, using Lapua brass also lowers velocity from book listings, as they usually spec Winchester or Federal brass. The Hodgdon 80SMK/Varget load I mentioned going 2864 with the specified Winchester brass,26" bbl), dropped to 2745 in Lapua brass. You say you got 2880 with that amount of Varget, so no way would I cut that barrel-it isn't a problem.
 
I didn't know that lapua brass would reduce velocity, I figured with a set charge you would get roughly the same velocity.
I'll have to try some of my lake city ar-15 brass.
thanks for the info.
 
Oh one thing to note is that my lapua is new lot and not the heavier thicker and less case volumn old lot of lapua.
I'll have to do a case volume to compare between my lake city, remington and lapua and see what the difference are.
I know typically lapuas will handle stouter loads than other brands of brass, but if I can gain velocity and get an accurate load by going to Winchester or lake city then I may try that.
I had an accurate load at 23 grains of varget then a real accurate load at 24.5. I am wondering though if the same load would create more pressure or less pressure in Winchester or Lake City brass versus the Lapuas.
I think it has to do with load density versus case volume for pressure but I can't remember if it also decreased or increased velocity.
 
Steve, I should clarify about the Lapua, saying I have found in 223 with the box of Lapua I bought, it lowered velocity from Winchester. I'm just referring to the 223 here, I don't want you to think I'm making a blanket statement about Lapua brass in general as I'm not.
The Lapua I have is just slightly heavier than LC, and a little lighter than average Winchester.

I have not tried the 80/Varget load in LC brass, but I can tell you that a load for 77SMK I tried ran 18fps faster in Winchester than in LC so not a big difference there.
I think you'll have better results with the Lapua. The velocities were more consistent in the Lapua for me. If you got that 30" barrel for 600yds or more, you will want a consistent load. Your 24.5 results are already promising, and produced 2803fps. Some fine tuning may get the results you're looking for.

As far as your pressure question, I'm thinking the pressure would go up in Winchester brass, since the velocity probably will,note the significant difference-over 100fps-I saw). In other words, I would lower the powder charge if you try the Winchester brass,to be safe) and see how it correlates to your Lapua velocity at the same charge weight.
 
I surveyed several powders developing loads for my .223,28" 1:7 Krieger, custom reamer) and get the best results with N-550. RL-15 wasn't very far behind, but pressures were noticeably higher. I suspect that RL-17 might be better than either, but I haven't had a chance to try it yet.
 
I just ran the numbers on quick load with r-17 and it looks like an awesome powder for the case/bullet. out of your 30" barrel it says you can expect 3100fps. if your trend holds up you should still be around 2950fps. So i definatly would try the R-17 if i was you
 
Steve, I shoot using a 30.5" Krieger, 1:8 twist with a Barnard bolt action. 25gr of Varget,AR2208 in Oz)with 80gr Sierra MKs sitting 0.005" off the lands,jump). This gives me a very consistent 2960fps and a very accurate target load for 300-1000yds.

A lot of shooters here in Oz use 25gr or more of Varget,AR2208)with either 80gr Sierra MKs or 80gr Hornady Amax projectiles. The club where I shoot has others with comparable rifles,single shot B/A)using 25.5gr of Varget for velocities around 3000fps.

Whoops, almost forgot to say that I use Lapua brass as do most target shooters in OZ. The brass I'm using has been shot 4 times so far and still looks like brand new with no pressure signs at all. I do use an ultrasonic cleaner and inspect all my brass after firing.

Hope this helps!
 

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