Bullet seating depth's for rifle barrel node

[warbucks]

Hi everyone.

So iv'e developed a optimal charge weight of 34.5 gn's of n140 for my Weatherby vanguard 22-250 24" barrel, using Hornady 55g v-max bullets, i started off with the standard over length of 2.350", this charge weight was stable, and gave the best groupings at 100 yds and this was around 1 1/4" or 32mm.

My question is this, if say in the above example id started off with a bullet seating depth of 2.400" and got a grouping of 1 1/2" or 40mm, and i then altered the bullet seating to 2.405" would the groupings progressively come better "IF" i am going the right way ie pushing the node to the mussel ------------or doesn't it work that way ?

Dave (warbucks)

[kennyc]

I dont load for 22-250, but your load appears high by Vhits load data, what speed are you getting ? and where did you get your data ? if you aren't getting pressure signs then all well and good, but it might be worth firing a lighter load and see what that does to the grouping before playing with lengths ?

[1873]

I use a Hornady Lock n Load OAL gauge for my Sako TRG22 and it's really tightened up the group size BUT I found that even more important than that was to ensure the concentricity of the loaded rounds. I bought a Hornady Lock n Load concentricity tool off thebay for half price of a new one and that was a revelation! My TRG will regularly and repeatedly shoot 0.25 moa (with witnesses at Kynamco range) if I take total care at my end of reloading, but that was increased to just under 1 moa using Federal Premium Gold or nearly 2moa using Privi match!!! Something I didn't expect was when I put factory rounds through the concentricity tool I found that the run out on even the most expensive factory (at the time it was £38 for 20) was erratic and accuracy could be tightened up enormously by doing the same thing with that.

Word of warning though - any deviation from standard oal - whether longer or shorter will make a difference to chamber pressure so ALWAYS look carefully at your fired cases for tell-tale signs, make changes very slowly and stop at the first unusual sign.

[223AI]

https://load-data.nosler.com/load-da...250-remington/

I tend to double check with nosler as often a bit more generous than Viht, if you are getting 1 1/4" i don't think changing COAL will dramatically reduce it, it may improve it but I'd be looking at a different bullet or if you want to stick with that bullet then try primer and powder.

FWIW the 50 gr v-max out of my 1:14 .223 AI is an awesome bullet and hammers foxes out to sensible ranges.

[warbucks]

Thanks all three of you for taking the time to give me your advice.

Dave (warbucks)

[baldycoot]

Not sure how far you want to go with your case prep but....

I found neck turning the cases made a significant difference.

[JB101]

Ideally you need to load up several ‘batches’ of differing lengths and bench test each for grouping starting at the minimum COAL and move up in say 5thou increments or 10 thou and when you see a distinct group reduction at a point you can then fine tune the length again by group testing.
To improve concentricity (& therefore consistency) of the rounds when seating the bullet once rotate the cartridge 180 degrees and reseat .

[warbucks]

Ideally you need to load up several ‘batches’ of differing lengths and bench test each for grouping starting at the minimum COAL and move up in say 5thou increments or 10 thou and when you see a distinct group reduction at a point you can then fine tune the length again by group testing.
To improve concentricity (& therefore consistency) of the rounds when seating the bullet once rotate the cartridge 180 degrees and reseat .

Thanks very much for this, iv'e already loaded some up at 5 thou increments just need to test them now.

I hate and detest developing new loads, try to short cut it as much as possible, never seem's to work.

Dave (warbucks)

[tacfoley]

https://load-data.nosler.com/load-da...250-remington/I tend to double check with nosler as often a bit more generous than Viht

Nosler make bullets, not powder, so where pressure figures are involved I'd tend to take notice of the powder-maker's figures.

[loiner1965]

Thanks very much for this, iv'e already loaded some up at 5 thou increments just need to test them now.

I hate and detest developing new loads, try to short cut it as much as possible, never seem's to work.

Dave (warbucks)

easiest way to sort seating depth out is with a lee hand loader.
set all cases at maximum col with your seating die in the handloader at the range or in the field ( all cases filled with same amount of powder etc ) then shoot a group off etc.
measure group size and col of ammo used.
now reduce all the remaining cases by 5 or 10 thou and test again and record.
keep reducing all remaining cases by same amount and repeat........
all i do is copy all nightstalkers loads and tailor them to my rifle like i did with my .223
with my other calibres like 308 and 30-06 i have been lucky and sussed a load out quite quickly

[Eyefor]

Hi everyone.

So iv'e developed a optimal charge weight of 34.5 gn's of n140 for my Weatherby vanguard 22-250 24" barrel, using Hornady 55g v-max bullets, i started off with the standard over length of 2.350", this charge weight was stable, and gave the best groupings at 100 yds and this was around 1 1/4" or 32mm.

My question is this, if say in the above example id started off with a bullet seating depth of 2.400" and got a grouping of 1 1/2" or 40mm, and i then altered the bullet seating to 2.405" would the groupings progressively come better "IF" i am going the right way ie pushing the node to the mussel ------------or doesn't it work that way ?

Dave (warbucks)

Sorry, but I think a 40mm group is very poor. Can you imagine what that group becomes at 300 yards and beyond - which your 22-250 is very capable of doing?

I and most reloaders I know - plus some very clever and patient reloaders that once taught me - all develop rounds by length and then load.

Start with an average recommended load for a particular powder, load 50 rounds at 5 thou off the lands. Take rifle, rounds and press with seater die to the range / zeroing point, fire 5 rounds at 100 yards then squeeze the next 5 in to 10 thou off the lands and so on until you find a five shot group that you're happy with. It should easily be sub 1/2". If you don't get 1/2" out of the first 50 rounds, load another 50 and start the process again where you left off.

Once you have that 1/2" group at 100 yards then try it at 200 yards. If it is sub 2" at 200 yards then keep that length and start tweaking the load in .2 or .3 grain increments to get the 200 yards to 1" (or better).

One 22-250 I had (Ruger MKII VT) would shoot almost everything very well. Another (Sako 75, stainless varmint barrel) was a pita and took many hours to sort ending up at 137 thou off and 38.1gr Varget.

It will drive you mad, but it is worth it.

[warbucks]

Sorry, but I think a 40mm group is very poor. Can you imagine what that group becomes at 300 yards and beyond - which your 22-250 is very capable of doing?

I and most reloaders I know - plus some very clever and patient reloaders that once taught me - all develop rounds by length and then load.

Start with an average recommended load for a particular powder, load 50 rounds at 5 thou off the lands. Take rifle, rounds and press with seater die to the range / zeroing point, fire 5 rounds at 100 yards then squeeze the next 5 in to 10 thou off the lands and so on until you find a five shot group that you're happy with. It should easily be sub 1/2". If you don't get 1/2" out of the first 50 rounds, load another 50 and start the process again where you left off.

Once you have that 1/2" group at 100 yards then try it at 200 yards. If it is sub 2" at 200 yards then keep that length and start tweaking the load in 2 or 3 grain increments to get the 200 yards to 1" (or better).

One 22-250 I had (Ruger MKII VT) would shoot almost everything very well. Another (Sako 75, stainless varmint barrel) was a pita and took many hours to sort ending up at 137 thou off and 38.1gr Varget.

It will drive you mad, but it is worth it.

Thanks very much Eyefor for this ---------------so if i load at 34.5 then alter the seating length by 5 thou over the minimum to maximum seating length your saying some where along this i will get 1/2 group.

Dave (warbucks)

[baldycoot]

Once you have that 1/2" group at 100 yards then try it at 200 yards. If it is sub 2" at 200 yards then keep that length and start tweaking the load in 2 or 3 grain increments to get the 200 yards to 1" (or better).

Is that meant to say 0.2 or 0.3 Grn increments?


Dave,

Some bullets just will not work in a particular rifle.

I must have tried 30 different bullets in my .223 and some of them will make tiny clusters all day long, but some just will not settle down, no matter what.
I found the same bullet issue with my .308 staking rifle only without the objective of making tiny clusters.

Before my .223 went in for a rebarrel I had four loads that were my goto loads, 52 grn AMax, 52 Grn SMK, 60 Grn VMax and 55 Grn Dog Town.

When the 60 Grn VMax were finished I tried to use the Sierra equivalent.
It was good out to 200 Yds and OK to 300, but would not work beyond that.
The Nosler equivalent worked as well as the VMax ever did all the way out to 600Yds.

When the 55 Grn Dog Towns were finished I tried to use the Sierra, Hornady and Nosler equivalent.
None would work consistently.
I eventually got those cheap and nasty PPU in 50 and 55grn to make consistent 0.5 MOA groups out to deer control ranges.

The SMK and AMax always performed consistently out to 400Yds, and were a dream to develop loads for, their BC falls off quickly beyond that so that was what they were devloped for.
When the 52Grn AMax went I changed to 53Grn VMax, and they worked just as well.

Also my 1-9 twist .223 wouldn't perform consistently with the heavier SMK, but it would shoot the 68Grn Hornady really well.

I have it all to do again when I get the rifle back, with a faster twist, but I'm actually looking forward to it.

I always work the load then the seating depth, it's each to their own so do what works for you, and I changed to using a lee hand press a few years ago whether in the field or at home.

[warbucks]

Thanks Baldycoot.

Well testing so far.
34.5 gn's of n140 was poi stable over a few gn's either side and wasn't showing any pressure sign's with the 55 g vmax
35.5 gn's of n140 for the 50 gn v max was just a "middle of the road" suggestion from some one -------but no pressure sign's.

N140 & Hornady 55 g vmax 34.5 gn's seating depths from 2.340'' -2.365'' in 5 thou increments, best group 25mm with 2.345"
N140 & Hornady 50g vmax 35.5 gn's seating depth. from 2.350 -2. 360. in 5 thou increments best group 25mm with 2.355" & 2.360"

Looks like i have a long way to go ----------i hate it.

Dave (warbucks)

[JB101]

Looking up the details on the rifle the barrel twist is 1:141/2 which generally means they like bullets below 55grains
It could be that your rifle does not get on with them so you may have to look at lighter bullets say in the 40-52 grain range.

ATB
James