Need help tuning my 2012 Bengal Pro
I have been trying to tune my Bengal Pro and need some help. The ATA is supposed to be 31" and brace is supposed to be 7". I had paper tuned it with a fletched shaft a couple weeks ago and had a pretty good lower left tear going. I moved the nock point up and it solved the low tear, however the nocking point was up around 3/8" higher than level. I also got rid of the left tear by moving the rest all the way to the right. I have the bow maxed at 70 pounds, and am using GT 7595.
Arrow flight was good after doing this, but I really didn't like how high the nock point was. Today I decided to start all over again and set the nock point level with the arrow going straight through the berger holes. I tried bare shaft paper tuning and again had the low left tear. This time I attempted to adjust the rest and got rid of the low tear, but the arrow lined up below the berger holes and had a pretty good downward lean.
I brought the bow inside and measured ATA and both sides and there was a difference from left to right of about 1/8" between the two sides with the ATA measuring approx. 31 1/4". The brace height was about 6 3/4". I removed the cable and twisted it and now both sides are around 31 1/8". One side is just a bit longer. Now the brace height is 6 13/16".
Looking for input on how to proceed getting this bow closer to spec. and would the way this bow was, give me the low left tears I was observing.
Need to leave for work but will check in when I get there.
Thanks in advance,
Probably answered my own question
Well, I looked through the easton tuning manual again and see that they recommend setting the nock point 1/4" high to begin with for a mechanical release, so I guess my nock point wasn't as out of wack as I thought. I should have pulled the manual up first but was running out of time as I needed to get to work. Guess the next step will be pulling the string and cable, factory installed, and making sure they are within spec. I have already noticed some serving separation down near the cam, so I need to decide if I want to throw a new set of strings on, as I will have the other's off. Only about 100 arrows through it at this point.
Paper tuning 2012 bengal pro problems
I am shooting a very similar set-up to you & have been experiencing great difficulty in getting the correct paper tuning results. This is the first bow I have owned so I could be missing something??
My set up:
2012 Bengal Pro, 68# (max it will go with 70# limbs?) 29" draw, Trophy Ridge Hitman 5, g5 1/4" meta, d-loop, QAD Ultrarest HDX, GT Expedition Hunter 7595 29" with NAP 2" ST Speed Hunter QuikSpins, 100 grain field tips & 100 grain Muzzy MX4 Broadheads, Apex Attitude 4oz Stabiliser, wrist sling.
When I got this bow it was set up with an octane hostage rest. The accuracy was pretty impressive after getting it sighted in I could put together a 5-6 shot group that had all arrows touching each other from 20m, well by the time I had put 50 arrows through it, it was as good as worn out so under recommendation, I set up a whisker biscuit power shot rest, I could never get the perfect paper tune result with this rest so ended up settling for the best I could. The groups were not anywhere near as tight as they were out of the hostage rest. When I swapped from field tips to broadheads the flight was sufficiently accurate enough & only required me to drop my sight by a small amount to have it dialed in close enough for hunting. Although the whisker biscuit is great for the spot & stalk type of bush hunting we have been doing, imo it is not the most accurate rest for shooting good tight groups on target. After doing some research I decided on the QAD Ultrarest HDX, I set it up according to the instructions & took it straight out for a shoot. I was blown away!! Groups from 20m were tight, all arrows touching most of the time, I took it right out to 60m and at that distance was getting a 6-8" group ( not too bad considering it had not been paper tuned ).
At this point I had not paper tuned it but was interested at seeing how it would fly straight off with a broadhead on. Now I probably should have started out at 20m with this but decided that where I was shooting a miss at 60m would not be the end of the world & the arrow could be found. I nocked up a broad head, set my sight pin on the bull & released waiting for the thud of the arrow hitting the target.... well, it never came, the arrows path was well right of the bull by 12-15" & low by at least 10".
Time to head back to the shed & try some paper tuning, I had a terrible result/tear, the arrow tip was hitting the paper lower & to the right of the vanes, I looked at the chart & saw that there was obviously more than one thing wrong. I tried moving the nock point to get until I just got a left tear. This wasn't working & nothing I could do would tune out the left tear.
Yesterday I got our local archery expert to check the cam timing & check the centre shot, we also lengthened the cable from the rest to the downward bus cable to make sure the rest was dropping early enough to avoid contact with the vanes, we took it out to the target & put a few more shots into the bag, I could tell by the way the arrow initiated its flight that it was dropping & steering to the right as it left the bow before straightening out again. One of the suggestions was that the arrow spine was too weak? On the goldtip chart, 7595s are perfect for my draw length & the bow poundage rating, I put the bow setup into the archery program along with the arrow data. Their scale showed this arrow being under spined for the bow as well.
We had a couple of Gold tip big game hunter arrows kicking around so we decided to throw a couple of field tips in & see how straight we were shooting. Arrows were side by side & looked to be coming out of the bow straight & not looking like a sidewinder missile tracking something. This was a good enough indication that the arrows were shooting straight so i threw a broadhead in one of them & had a shot aiming at the same point as before. the line was perfect but a little high. That backed up the fact that maybe we were under spined. Back to the shed for more paper testing. By adjusting the nock point I could get the arrow to a point where it was only showing a left tear, this is the big game arrow at 29", I cut one of the 7595s down to 28" to see if this would stiffen things up a bit. Now I was getting a similar tear from both the arrows. (the longer tears were from the 29" 7595s.
I still can't seem to get the left tear out of my shots, the shots were taken at a distance of about 8-10 feet from the paper. I will try baby powder on the vanes to see if any contact is being made tomorrow. It is becoming frustrating not being able to get a good tear pattern & especially not knowing how to remedy it??? I do not hold the grip on release, it is sitting in my hand with only my thumb & fore finger touching each other so I don't believe I am torquing the shot on release?
Keith, I would be interested to know what the dimension you have from the riser to the inner line of the arrow shaft? This way I can check my set up for some comparison.
Does any one have any suggestions that I could try to get these arrows to bullet hole? I would really like to get this sorted as it is prime time for fallow deer hunting here at the moment. I want to know that when i take a shot it is going to go where it should go.
Thank you all for your time & I hope someone can offer some experience & advice.