243 load questions

[fishfurlife]

Okay, for starters, I have been having heck with this specific gun over the last 6 months.

I am shooting a Remington Model 700 in 243. Just a run of the mill Remington. I did enough looking to figure out that the gun should have a 1 in 10 twist based on the serial number. I know a 1 in 10 would limit me on the size of bullet that I could get to stabilize and be accurate and consistent.

After trying all kinds of different loads/variations of loads I just wanted to throw in the towel (3 months or so). I have a friend that has a custom gun shop and he suggested swapping barrels on the gun. He has a good number of factory barrels that were taken off to upgrade the rifles. Recently I swapped the barrel out for a barrel with a 1 in 9.5 measured twist. We also measured the twist on the original barrel............. We measured it 4 different times and came up with a 1 in 12.5 twist each time. This made me feel so much better because I thought I was going nuts. I was a little upset at the same time though. I was trying to shoot 80-95 grain bullets and was getting junk for grouping. It all made sense after this. Looking back, I should have checked the twist in the beginning.

After shooting the gun a bit and tinkering with loads I have a question the seasoned hand loaders. Just how close can a guy get the bullet to the lands without causing big issues?? I know there has to be some space between the two and understand why, however, my question is what are you guys experience with this?

 

[oneof79]

Some of my loads for my Ar start about .010 away from the lands. I lose a couple of thousandths every 100 rounds or so. For accuracy some guys cram the bullet into the lands. These loads probably won't be published and you would have to work up to them. I think alot of people shooting lead bullets in old military rifles do this alot.

 

[Okie4570]

What he said above That's strange on your original barrel twist, .243's came out with 1-10 twists from the get go, rems .244 came out with 1-12 and would'nt stabilize the heavies so they renamed to 6mm and redid twist to 1-9. Hope it's shoots better for you.

 

[aeropb]

It is possible to seat a bullet touching the lands and have no issues.

 

[Okie4570]

As long as there's a reduction in powder, this is how fireformed cases are made. .280AI for example is a standard .280 with a reduced powder charge, bullet touching lands and fired in .280AI chambered rifle. Pressure reforms brass to new chamber. Hope I didn't just tell you something you already knew, if so sorry

 

[1mathom1]

I have never measured how far off the lands I am seating them but here is the method I use and it seems to work well.
Using ajust a bullet in a resized but EMPTY case, I first seat the bullet to just over the length of a factory load. I color the bullet with a black marker and wth the rim under the extractor I start the cartridge into the chamber. I stop when I feel resistance and remove the cartridge making sure it was the rifling that cause the resistance. Use a careful touch....otherwise you can jam the bullet in the rifling and pull it out of the cartridge. Once I am sure the resistance was from rifling touching the bullet (by looking at the marks in the black marker ink), I go about an 1/8 of turn on the seater and try again. I keep at it until I no longer see rifling marks on the bullet after full bolt lock up. That cartridge become my bullet seater gauge till I change bullets....then I make a new one. Not real scientific but it works. With my old Winchester M670, groups are a little better using this method rather than using what the book says is max cartridge length.....no pressure issues. My Ruger doesn't care...same size groups (and not as good as my old Winnie either). Both in .270 using Nosler ballistic tips...same brand cases, primers and powder. I cannot seat the bullet far enough out to touch the rifling on my FIL's old .303 Brit....imagine that.

 

[DRC458]

Using ajust a bullet in a resized but EMPTY case, I first seat the bullet to just over the length of a factory load. I color the bullet with a black marker and wth the rim under the extractor I start the cartridge into the chamber. I stop when I feel resistance and remove the cartridge making sure it was the rifling that cause the resistance. Use a careful touch....otherwise you can jam the bullet in the rifling and pull it out of the cartridge. Once I am sure the resistance was from rifling touching the bullet (by looking at the marks in the black marker ink), I go about an 1/8 of turn on the seater and try again. I keep at it until I no longer see rifling marks on the bullet after full bolt lock up. That cartridge become my bullet seater gauge till I change bullets....then I make a new one.

Took the words right out of my mouth!

 

[fishfurlife]

Thanks for the advise guys. I will put it to use. I am already outside of the max cartridge length but not by a whole lot. I just wanted some thoughts before I went to moving it out farther.

 

[MoBoost]

What kind of accuracy we are talking about?

IMHO bullet jump is the least important part of the accuracy equation; the common notion is that the longer the jump the more "time" bullet has to yaw; I'm saying if your neck tension is uniform it will not yaw, if neck tension isn't uniform - even jamming won't help with yaw.

Example: Swedish M96 are reamed for 160gn round nose bullet - and yet we achieve GREAT accuracy with 110-130gn VLD; we are talking about .300-.500" jump.

We've contacted Sierra and they said to forget about the jump in non-custom chambers: just seat the bullet where bullet/neck contact length equals the bore. From my experience the COL in the reloading manuals turns out to be following the same formula. I also noticed that on 308s cannelure is at perfect height, while sub-308 calibers cannelure is way too high.

Jamming has two problems:
1) If you don't trim your brass and it jams into the throat; that + bullet in lands might cause dangerous increase in pressure
2) If seating depth is shallow and you have weak neck - clearing the rifle might pull the bullet out and make a gun powder mess all over the action.

 

[Ksmirk]

I have seated into the lands and jump bullets depends on what the rifle is for, I reamed the throat on my 7WSM pistol for a .010" jump with A-Max, the 243 likes .025" and the 308 jumps .040"

Have you messed with powder charge? there's the ladder chart that I never got to work like most so I just load up 3 or 5 rounds in .5gr increments and shoot for groups and when I find the sweet spot I adjust in .1gr increments until I find the load. I seat all to the same COL just adjust group with powder charges.

I have spent hours at the range with my hand loaders adjusting the COL and truth the best thing I have found for my rifles is trim the brass to the same length. There are all sorts of things you can do for accuracy but not being mean but most of us don't shoot well enough to notice.

That 1-12 barrel should have shot the 80gr bullets very well! I had a 22-250 Remington and we just unscrewed the tube cut off .100, rethreaded and rechambered correctly and it would shoot rather well for a factory barrel. Simple is the best. Later,

Kirk