Been working on some loads for my new 7mm08 and have noticed that the barrel is really slow. Has about 125 round fired and should speed up but not enough to get on track where it should be. I'm getting starting charge velocities at max charge weights. Barrel is a 24 1-9.5 twist made by Shaw and currently working with powders on the medium to slow side with 150gr bullet weights. Maybe try a faster powder?
Best way to handle a slow barrel?
- Thread starter Lefty Trigger
- Start date
The throat is a little short for the heavier bullets as some are close to the shoulder when seated. I'm trying to stay away from powders that compress know the bullets are deep and I'm seating at .020 off for starting point. Using 150gr Lapua Scenar-L and Nosler Ballistic tip. I have lighter down to 120gr and heavier up 168gr but it don't seem to like the lighter bullets. So far Varget and H4350 are the only powders that give tight bolt lift at max loads or up to .4 over.
Slow is ok if it is accurate, speed kills accuracy. Rather have a slow accurate barrel than a fast barrel thats not accurate.
100 fps slower than average barrel with same twist, same bullets and same powder with same charge. Also using same reamer for chamber.
dmoran
Donovan Moran
If it is not a hand lapped barrel, and the barrels your comparing to are, would be a possibility to why.
Off the shelf barrel and that's what they had. Generally I never have any luck with large calibers but I'm loving this 7mm. I think when I finally get it dialed in it's going to be awesome. Had really good luck today with H4831sc and the Lapua 150gr, kinda slow but super accurate and I don't need speed for short distance anyway.
JEFFPPC
Gold $$ Contributor
Gotta strongly disagree. To make the statement speed kills accuracy is flat out inaccurate. Some barrels, bullets etc might be more accurate slow than fast but in 50 plus years of reloading I have found more that shoot best towards that fast side than the opposite. I do totally agree with you that accurate trumps fast. I never go into load developement with the idea I need x amout of velocity. Once I find an accurate load then I check velocity as a means to keep tune with powder, temperature, etc. variations.
Maybe I should have stated when I have went to top speed for barrel I was working on. I would have to back off top speed to fine best accuracy for that bullet, powder and barrel.
JEFFPPC
Gold $$ Contributor
I am good with that.You need to find a node it likes. Sometimes you top out between nodes,thus you must back up a bit.If you gain 50 fps but loose a tenth or a half tenth in accuracy that is not a good trade off.
I know moly is out of favour at the moment, and I only use it in 2 barrels, but I wonder if molying your bullets might help with your barrel? I usually found that running moly bullets worked well in tighter barrels which built up more pressure and it might allow you to get up a little closer to a node if you are just below one?
muleman69
USMC -1st marine Div. RVN
Have been there before
Uncle Mike
Gold $$ Contributor
If your barrel is too slow then roll it down a steeper hill.
Upgrades & Donations
This Forum's expenses are primarily paid by member contributions. You can upgrade your Forum membership in seconds. Gold and Silver members get unlimited FREE classifieds for one year. Gold members can upload custom avatars.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.
Click Upgrade Membership Button ABOVE to get Gold or Silver Status.
You can also donate any amount, large or small, with the button below. Include your Forum Name in the PayPal Notes field.
To DONATE by CHECK, or make a recurring donation, CLICK HERE to learn how.