Can someone explain what was happening please?

kb007

kb007

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I was out yesterday at 100 yds trying out a .223 bunch of loads for the new 700 5R that I recently purchased. Not the first time, had it out last week too. Everything was going well, I had a selection of bullets , mostly 68 & 75 gr Hdy Match bthp, plus the 75gr moly and 75 gr Amax. All of these were with imr4320 powder.

I noticed when I seated the Amax, they are a little longer than all of the rest, but was still able to seat them (as the rest) to 2.250".

Grouping were good, some better than others (that's the point of testing), but all between .5" and 2".

Then I got to the Amax. I had 2 loads, first was 22.5 gr, second was 23 gr. The first group was kinda lousy about 1.75". When I got to the second group, I couldn't see where they were hitting at all. I was using the Red star triple three targets and up to now every shot had been on the paper. I shot 4 from the 23gr amax group and only 1 actually hit the paper. I know they weren't going real high or low as there was a foot at least of paper around each target. One of them had a poi of about 1" left and 1/2" low of my point of aim. I grabbed another load and they shot just fine, so it wasn't like the scope suddenly lost it's zero.

Did they break up somehow? or what was going on?
 
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You should never switch between moly coated bullets and non moly coated bullets with cleaning your bore right down to bare metal. When using moly you will need to bump up your load about .5 gr to get the same velocity as bare bullets. I have heard of AMax bullets blowing up in mid flight but these were at 6.5-.284 velocities.

I have found AMax bullets to be hit or miss (no pun intended) I had one barrel that shot them like a laser while other barrels would only hold the 4 ring at 300m. I did find that .020" off the lands worked best in that barrel, while my buddy's rifle liked them jammed into the lands.
 
kb007 said:
I noticed when I seated the Amax, they are a little longer than all of the rest, but was still able to seat them (as the rest) to 2.250".

?
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I would seat them out much longer, try a .010 jam and .010, .020 jump. They like to be seated closer to the lands and at 2.25 coal you likely have a huge jump. Also if you have it try varget for your powder. A .020 jump with varget has always worked well for me. What is the twist of your barrel?
 
It's possible that because the Amax are "a little longer than the rest", that they aren't stabalizing in your barrel. Move the target closer, so you can't miss the paper and look for signs of keyholing.
 
Barrel is 1 in 9. Never thought about them being de-stabilized. May be that's just a load I won't bother re-testing.

I'll prolly try some loads with Varget next weekend btw.
 
I believe your barrel is 1:9 twist, I also believe Hornady calls for 1:8 for anything over their 68gr.

9.3mauser is on to something ;).

I'd suggest a smaller bullet and a faster powder.
70gr Berger VLD / Varget, for example.
 
Also you're seating the Amax way to short at 2.250" in a 223... :O I dont shoot them but everything i've ready says mag length with an Amax performs like dog poo...
 
Seat them to the lands if you can. Being a Remington you might not be able to get to the lands but the closer the better. Your seating depth is meant for ar15 mags
 
kb007 said:
I was out yesterday at 100 yds trying out a .223 bunch of loads for the new 700 5R that I recently purchased. Not the first time, had it out last week too. Everything was going well, I had a selection of bullets , mostly 68 & 75 gr Hdy Match bthp, plus the 75gr moly and 75 gr Amax. All of these were with imr4320 powder.

I noticed when I seated the Amax, they are a little longer than all of the rest, but was still able to seat them (as the rest) to 2.250".

Grouping were good, some better than others (that's the point of testing), but all between .5" and 2".

Then I got to the Amax. I had 2 loads, first was 22.5 gr, second was 23 gr. The first group was kinda lousy about 1.75". When I got to the second group, I couldn't see where they were hitting at all. I was using the Red star triple three targets and up to now every shot had been on the paper. I shot 4 from the 23gr amax group and only 1 actually hit the paper. I know they weren't going real high or low as there was a foot at least of paper around each target. One of them had a poi of about 1" left and 1/2" low of my point of aim. I grabbed another load and they shot just fine, so it wasn't like the scope suddenly lost it's zero.

Did they break up somehow? or what was going on?
Click to expand...

Just a suggestion here, but reading this made me wonder if you are introducing too many variables too quickly to get any usable testing results. Unless i misunderstood, you are talking about shooting 2 and 4 shot strings and then trying a vastly different load out. This is insufficient to determine anything, especially when you factor in shooter variation shot to shot. May I suggest you slow down, pick a load and tweak only one variable at a time with something more like 4 identical strings of 5 shots each until you find the best combination of bullet, powder, charge, seating depth etc...

Sorry in advance if I misread your post.
 
When I'm testing like this I make 10 rounds of each combination, shooting 5 round groupings. It's an attempt at trying heavier bullets in this gun as a test. Up to now I've only used up to 55 gr. Interestingly the best grouping I had was from the 75gr moly.
 
1) OAL is a completely useless measurement when comparing one bullet to another. What matters is where the ogive of the bullet sits in relation to the lands in your particular gun. From a tangent to a secant ogive bullet. the difference for a single OAL can be HUGE. OAL is only relevant insofar as magazine length is concerned.

2) as to disappearing bullets, it sounds like a stabilization issue... 23 grains of 4320 is a bit of a whimpy powder/load for that bullet weight (odd because Varget is very similar in burn rate but produces better performance) . It may be they didn't have the velocity to stabilize properly in that twist.

3) was it you? could you have made a mistake in relooding? Can you pull a bullet an measure your powder?
 
paperslayer said:
2) as to disappearing bullets, it sounds like a stabilization issue... 23 grains of 4320 is a bit of a whimpy powder/load for that bullet weight (odd because Varget is very similar in burn rate but produces better performance) . It may be they didn't have the velocity to stabilize properly in that twist.

3) was it you? could you have made a mistake in relooding? Can you pull a bullet an measure your powder?
Click to expand...

Weird that the 22.5 gr loads worked fairly well, but the 23 gr loads vanished. The 4320 range was something like 22.5 to 24.5 (HDY iirc). I'll pull one on the weekend just to dbl check, but I was weighing each case/powder so doubtful, but not impossible, and very unlikely I'd make the same mistake 4 of 5 times with only that bullet and not others (honestly occifer I washn't drinkink at the time...)

For now, I guess I'll have to presume that for 4 of 5 there was some weird stabilization issue, either that or aliens took ma bullets ;)
 
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