Hornady .309 90gr. XTP bullet testing...
Posted: Mon Apr 01, 2013 10:12 pm
I just bought 1,000 Hornady .309 90gr. XTP bullets for use in my 300 Blackout & .308 Win. bolt guns. I`ve heard of others using this bullet in the 300 Blackout with some success so I was looking forward to experimenting some with this bullet with a primary emphasis on subsonic applications and to a lesser extent supersonic.
I loaded up a bunch of rounds and headed to the range yesterday. I loaded the bullets at a COL of 1.85`` using Trail Boss at .2gr. incriments from 4.8gr. to 5.4gr. of powder. I loaded (15) rounds at each charge weight with and without a moderate crimp from a Lee FCD. Primer of choice was Win. Small Rifle Standard.
My primary goal was to see if I could find an accurate subsonic 300 Blackout load using Trail Boss with the tiny 90gr. XTP bullet and to determine wether crimping made any difference in accuracy. No velocity measurements were taken because it was secondary to finding an accurate load.
As others have reported, the 300 Blackout loaded with the 90gr. XTP bullets are too short to reliably feed from internal box magazines of bolt guns. I loaded a dummy round and tested feeding from a Remington 700 and a Weatherby Vanguard rifle. The Weatherby has fed everything I`ve ever loaded without any issues so I was curious to see if that would hold true with the XTP.
Unfortunately, I can confirm what others have already reported. The small XTP feeds poorly and the only way I could make it feed at all was by running the bolt hard and it was no means a guarantee that it would work. So, it was a single feed affair. Loading each round by hand into the chamber and then closing the bolt on the round.
Based on what others have reported, 4.8gr. of Trail Boss was reasonably accurate, though my Rem 700 preferred 5.0gr. by a small margin. My Anything past 5.0gr. and the groups opened up in size. All loads tested shared a distinct preference for NO crimp. All testing was done at a distance of 100 yards.
(3) 5-shot groups loaded with 5.0gr. Trail Boss and no crimp measured: 1.676``, 1.003``, and 1.382`` respectively for an average of 1.354``. I`m fairly pleased with initial testing and some slight improvement might be had by trying different primers.
Testing with Trail Boss was not without some head scratching moments, however. Some groups had unexplicable flyers where rounds would impact well below the others. The rounds that fell short sounded weak when fired, as though the powder charge was off or there was incomplete ignition.
I went to great lengths to ensure that the powder charges were consistent and I made a habit of measuring each charge weight twice, knowing that even the slightest variance might have a detriment on accuracy when dealing with such light loads.
So, for the next phase of testing I plan on loading more rounds at 5.0gr. of Trail Boss and try some different primers. I have CC450, Federal 200, Federal 205, Win. Small Pistol Standard, Win. Small Pistol Magnum, and possibly some Rem. 7.5 Benchrest on hand. With any luck, I`ll find more consistency in loads and possibly some slight improvement in accuracy.
I`ll post more results when I get out to the range. Weather conditions aren`t favourable for the balance of this week and winds will be high.
I loaded up a bunch of rounds and headed to the range yesterday. I loaded the bullets at a COL of 1.85`` using Trail Boss at .2gr. incriments from 4.8gr. to 5.4gr. of powder. I loaded (15) rounds at each charge weight with and without a moderate crimp from a Lee FCD. Primer of choice was Win. Small Rifle Standard.
My primary goal was to see if I could find an accurate subsonic 300 Blackout load using Trail Boss with the tiny 90gr. XTP bullet and to determine wether crimping made any difference in accuracy. No velocity measurements were taken because it was secondary to finding an accurate load.
As others have reported, the 300 Blackout loaded with the 90gr. XTP bullets are too short to reliably feed from internal box magazines of bolt guns. I loaded a dummy round and tested feeding from a Remington 700 and a Weatherby Vanguard rifle. The Weatherby has fed everything I`ve ever loaded without any issues so I was curious to see if that would hold true with the XTP.
Unfortunately, I can confirm what others have already reported. The small XTP feeds poorly and the only way I could make it feed at all was by running the bolt hard and it was no means a guarantee that it would work. So, it was a single feed affair. Loading each round by hand into the chamber and then closing the bolt on the round.
Based on what others have reported, 4.8gr. of Trail Boss was reasonably accurate, though my Rem 700 preferred 5.0gr. by a small margin. My Anything past 5.0gr. and the groups opened up in size. All loads tested shared a distinct preference for NO crimp. All testing was done at a distance of 100 yards.
(3) 5-shot groups loaded with 5.0gr. Trail Boss and no crimp measured: 1.676``, 1.003``, and 1.382`` respectively for an average of 1.354``. I`m fairly pleased with initial testing and some slight improvement might be had by trying different primers.
Testing with Trail Boss was not without some head scratching moments, however. Some groups had unexplicable flyers where rounds would impact well below the others. The rounds that fell short sounded weak when fired, as though the powder charge was off or there was incomplete ignition.
I went to great lengths to ensure that the powder charges were consistent and I made a habit of measuring each charge weight twice, knowing that even the slightest variance might have a detriment on accuracy when dealing with such light loads.
So, for the next phase of testing I plan on loading more rounds at 5.0gr. of Trail Boss and try some different primers. I have CC450, Federal 200, Federal 205, Win. Small Pistol Standard, Win. Small Pistol Magnum, and possibly some Rem. 7.5 Benchrest on hand. With any luck, I`ll find more consistency in loads and possibly some slight improvement in accuracy.
I`ll post more results when I get out to the range. Weather conditions aren`t favourable for the balance of this week and winds will be high.