Why use different alloys in BPCR

[Fiatmom]

I was wondering why BPC calls for 20 to 1, to 40 to 1 lead alloy. I have shot everything from pure lead to range lead to Lyman alloy.
I noticed a bit of difference in the filling of the mold, but accuracy seems fine.
I size to groove diameter so bumping up does not seem necessary. Why why are the soft alloys preferred?
Thanks
Nick

[gunlaker]

Using less tin is cheaper so a lot of people want to minimize that.

Just pick the one that shoots best with your load. I use 20:1 for Creedmoor style bullets and 16:1 for pointier noses.

Chris.

[bobw]

In a tight chamber for ppb like my business rifle chambered in 45 -2 7/8" I can easily shoot 1 in 60 alloy , my 40-90 2 5/8" sbn and 40-70 2.1" both thrive on 1 in 40. I can't tell much difference in my 45 -70 with 1in 25 compared to 1 in 30 with patch to bore diameter bullets that have a round nose. I don't use any money bullet design and get a long fine. My bullets all come from nose pour molds which gives them an automatic meplat they are all cupped base also. I alloy all my own. It saves money..bobw

[Don McDowell]

Depends on several different things but mostly what sort of accuracy your after
But by and large 20-1 and 16-1 will be the best
Keep in mind that the ODGs used bullets as hard as 11-1

[Luke]

Another variable in the search for accuracy.

[Fiatmom]

Thanks

[desert deuce]

Depends upon your purpose in shooting.

Are you trying to hit a 12" paper plate at 100 yards, OR, is your goal sub half minute 10 shot groups at 600 yards?

If the former alloy probably doesn't matter too much, IF the ladder my experience indicates alloy usually seems to matter quite a bit.

BUT, you didn't mention what your goals are.

[mike herth]

your goal sub half minute 10 shot groups at 600 yards?

DD, 10-shot 3" or less groups at 600 yards? How many scores at the DI reflect this? I'd be ecstatic if I could achieve that occassionally at 200 yards with just 5 shots.

[desert deuce]

fiatmom asked about alloys.

My answer asks indirectly what is he trying to accomplish and at what distance.

So Mike, answer me this? You are pulling a 600 yard target in a midrange match. The shooter fires their 4 sighters and 10 record shots.
I will do the math for you and the readership, that was 14 shots in the designated time.

In the target bucket by your right foot is a tape measure which you pick up and measure that 14 shot group.
It is exactly 10 inches wide and 1 1/2 inches high. 8 of the shots are laterally spread across the center of the X ring.

When you talk to the shooter they and their spotter tell you that there were no sight adjustments during the shooting of the 14 shots.
What does the 1 1/2 inch vertical say about the rifle, load & shooter that just shot that group using iron sights, .44 cal rifle.

Or, another time and place (Raton) still 600 yards. First shot nicks the wooden pin as do the next 4 shots leaving a hole about 1 inch in diameter for the five consecutive shots using iron sights. Five shots in one inch at 600 yards.
This was shot with iron sights, 40 cal rifle.

Want to take it to the next level? Take I-25 South to I-40, West on I-40 to I-17, I-17 South to exit 223, turn West 150 yards, right into entrance Ben Avery Rifle Range. Simple as that.