240 XTP Mag - Going the same way

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240 XTP Mag - Going the same way

Postby Hoot » Sun Jun 06, 2010 7:38 pm

I had the opportunity to try loading the Hornady 240gr XTP Magnum bullet over Lil Gun fired by the Remington 7 1/2 primer. Due to its lack of ballistic tip, the OAL looks short, but it's not really. It did strike the barrel extension lower than I would have preferred during chambering, leaving a distinct copper dot where it repeatedly hit. I had not considered loading it as it costs the same as the 225gr FTX bullet and I liked the BC of that round better. What follows is a table of the loads I had a chance to run:

Image

For this outing, once again 38gr (80%) of Lil Gun traveling an average of 2250fps rules the roost at 100 yards. Not my best group, but here's the target that gained this load a Hoot's Pick

Image

In the table, I forgot to mention I used just the taper crimp set to yield a mouth diameter of .475 inches. It pressed nicely into the cannelure.

Image

Base expansion ranged from .003" at 35gr Lil Gun to .0035" at 40gr Lil Gun.

When I get a chance, I'll try some faster loads, but those speeds, like in the case of the FTX family, will cause over-expansion at close range.

Hoot
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Re: 240 XTP Mag - Going the same way

Postby Siringo » Sun Jun 06, 2010 8:08 pm

Using this bullet, my best was 36.2 grs of LG, but using WSR. Group size similar. Velocities similar.
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Re: 240 XTP Mag - Going the same way

Postby Hoot » Sun Jun 06, 2010 8:41 pm

Siringo wrote:Using this bullet, my best was 36.2 grs of LG, but using WSR. Group size similar. Velocities similar.


I'm starting to have some doubts about my taper crimp. I assumed it crimps the upper 1/3 of the case an equal amount, but mine always looks like it's crimping the area near the mouth more than further down near the base of the bullet. I sometimes turn my cases to a brushed finish with a new bullet to see where the dies and the chamber act upon them. It can be rather enlightening. Easy to do too. Chuck them in the Lee case trimmer mandrel and a hand drill and gently pinch them with a scotchbrite pad while spinning. Shows up any contact they incur. Causes as many questions as it answers sometimes. :roll:

I didn't feel like I was in my Zone today at the range. Groups could have been better. Some days are like that...

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Re: 240 XTP Mag - Going the same way

Postby Hoot » Thu Dec 17, 2020 7:34 pm

This is in response to me linking this old thread for someone today:
My original 450b upper had a looser than average chamber. Made for ease of cycling but tended to produce pressure symptoms based upon case growth. My Bartz upper that I have now, has a phenomenal chamber and loads that back in that time frame, produced what appeared to be signs of pressure, now do not. So take the part about case growth from back then, with a grain of salt. Of course, little applies to bolt action rigs, which didn't exist back then, except by custom build.

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Re: 240 XTP Mag - Going the same way

Postby Al in Mi » Fri Dec 18, 2020 5:31 am

Holy smokes bud, that was 10-1/2yrs ago!!!! Hard to believe we've all been playing in this ole sand box for that long :shock:

I'll add this to Lilgun loads for the AR guys, somewheres about 4-5 years back there was a "hot lot" of Lilgun which was about 1-1/2 - 2gr faster than what most of the loads back then were posted with. Not sure what todays lot's are in relations, but as always, start lower and work up ;)
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Re: 240 XTP Mag - Going the same way

Postby Hoot » Fri Dec 18, 2020 6:27 am

Al in Mi wrote:Holy smokes bud, that was 10-1/2yrs ago!!!! Hard to believe we've all been playing in this ole sand box for that long :shock:

I'll add this to Lilgun loads for the AR guys, somewheres about 4-5 years back there was a "hot lot" of Lilgun which was about 1-1/2 - 2gr faster than what most of the loads back then were posted with. Not sure what todays lot's are in relations, but as always, start lower and work up ;)


That's a valid, good point Al. All serious reloaders should already accept that powders can change characteristics over time despite the manufacturer not forewarning their customers. That should reinforce the timeless reloading tenet of starting low and working up.

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Re: 240 XTP Mag - Going the same way

Postby PRKL8R » Fri Dec 18, 2020 7:23 am

+1 I've been loading for 40+ years and have powders that were almost that old due to maybe only to load a few rounds per year. That was especially true with small capacity cartridges such as 22hornet. A pound can last a very long time. This happened to me with the afore mentioned hornet and 2400 . Had a pound so old the price label had faded out, but it was around $10! When finnally replaced noticed a pressure change ( lower). So yes be carefull with every change of new lots of powder.
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